Mean Arterial Pressure and Neonatal Outcomes in Pregnancies Complicated by Mild Chronic Hypertension

OBJECTIVE

To estimate the association between mean arterial pressure during pregnancy and neonatal outcomes in participants with chronic hypertension using data from the CHAP (Chronic Hypertension and Pregnancy) trial.

METHODS

A secondary analysis of the CHAP trial, an open-label, multicenter randomized trial of antihypertensive treatment in pregnancy, was conducted. The CHAP trial enrolled participants with mild chronic hypertension (blood pressure [BP] 140-159/90-104 mm Hg) and singleton pregnancies less than 23 weeks of gestation, randomizing them to active treatment (maintained on antihypertensive therapy with a goal BP below 140/90 mm Hg) or standard treatment (control; antihypertensives withheld unless BP reached 160 mm Hg systolic BP or higher or 105 mm Hg diastolic BP or higher). We used logistic regression to measure the strength of association between mean arterial pressure (average and highest across study visits) and to select neonatal outcomes. Unadjusted and adjusted odds ratios (per 1-unit increase in millimeters of mercury) of the primary neonatal composite outcome (bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, or intraventricular hemorrhage grade 3 or 4) and individual secondary outcomes (neonatal intensive care unit admission [NICU], low birth weight [LBW] below 2,500 g, and small for gestational age [SGA]) were calculated.

RESULTS

A total of 2,284 participants were included: 1,155 active and 1,129 control. Adjusted models controlling for randomization group demonstrated that increasing average mean arterial pressure per millimeter of mercury was associated with an increase in each neonatal outcome examined except NEC, specifically neonatal composite (adjusted odds ratio [aOR] 1.12, 95% CI, 1.09-1.16), NICU admission (aOR 1.07, 95% CI, 1.06-1.08), LBW (aOR 1.12, 95% CI, 1.11-1.14), SGA below the fifth percentile (aOR 1.03, 95% CI, 1.01-1.06), and SGA below the 10th percentile (aOR 1.02, 95% CI, 1.01-1.04). Models using the highest mean arterial pressure as opposed to average mean arterial pressure also demonstrated consistent associations.

CONCLUSION

Increasing mean arterial pressure was positively associated with most adverse neonatal outcomes except NEC. Given that the relationship between mean arterial pressure and adverse pregnancy outcomes may not be consistent at all mean arterial pressure levels, future work should attempt to further elucidate whether there is an absolute threshold or relative change in mean arterial pressure at which fetal benefits are optimized along with maternal benefits.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT02299414.

A Multi-Site Study to Develop and Validate First Trimester, Circulating Microparticle Biomarkers for Tiered Risk Stratification of Spontaneous Preterm Birth in Nulliparas

BACKGROUND

Despite much research, advances in early prediction of spontaneous preterm birth (sPTB) has been slow. The evolving field of circulating microparticle (CMP) biology may identify novel blood-based, and clinically useful, biomarkers.

OBJECTIVE

To test the ability of a previously identified, 7-marker set of CMP-derived proteins from the first trimester of pregnancy, in the form of an in vitro diagnostic multivariate index assay (IVDMIA), to stratify pregnant patients according to their risk for sPTB.

STUDY DESIGN

We employed a previously validated set of CMP protein biomarkers, utilizing mass spectrometry assays and a nested case-control design in a subset of participants from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-be (nuMoM2b). We evaluated these biomarkers in the form of an IVDMIA to predict risk for sPTB at different gestational ages. Plasma samples collected at 9- to 13-weeks' gestation were analyzed. The IVDMIA assigned subjects to one of three sPTB risk categories: low risk (LR), moderate risk (MR), or high risk (HR). Independent validation on a set-aside set confirmed the IVDMIA's performance in risk stratification.

RESULTS

Samples from 400 participants from the nuMoM2b cohort were used for the study; of these, 160 delivered <37 weeks and 240 delivered at term. Through Monte Carlo simulation in which the validation results were adjusted based on actual weekly sPTB incidence rates in the nuMoM2b cohort, the IVDMIA stratifications demonstrated statistically significant differences among the risk groups in time-to-event (birth) analysis (p < 0.0001). The incidence-rate adjusted cumulative risks of sPTB at ≤ 32 weeks' gestation were 0.4%, 1.6%, and 7.5%, respectively for the LR, MR, and HR groups, respectively. Compared to the LR group, the corresponding risk ratios (RR) of the IVDMIA assigned MR and HR group were 4.25 (95% CI 2.2 to 7.9) and 19.92 (95% CI 10.4 to 37.4), respectively.

CONCLUSION

A first trimester CMP protein biomarker panel can be used to stratify risk for sPTB at different gestational ages. Such a multi-tiered stratification tool could be used to assess risk early in pregnancy to enable timely clinical management and interventions, and, ultimately, to enable the development of tailored care pathways for sPTB prevention.

Socioeconomic Disadvantage in Pregnancy and Postpartum Risk of Cardiovascular Disease

BACKGROUND

Pregnancy is an educable and actionable life stage to address social determinants of health (SDOH) and lifelong cardiovascular disease (CVD) prevention. But the link between a risk score that combines multiple neighborhood-level social determinants in pregnancy and the risk of long-term CVD remains to be evaluated.

OBJECTIVE

To examine whether neighborhood-level socioeconomic disadvantage measured by the Area Deprivation Index (ADI) in early pregnancy is associated with a higher 30-year predicted risk of CVD postpartum, as measured by the Framingham Risk Score.

METHODS

An analysis of data from the prospective Nulliparous Pregnancy Outcomes Study-Monitoring Mothers-to-Be (nuMoM2b) Heart Health Study longitudinal cohort. Participant home addresses during early pregnancy were geocoded at the Census-block level. The exposure was neighborhood-level socioeconomic disadvantage using the 2015 ADI by tertile (least deprived [T1], reference; most deprived [T3]) measured in the first trimester. Outcomes were the predicted 30-year risks of atherosclerotic CVD (ASCVD, composite of fatal and non-fatal coronary heart disease and stroke) and total CVD (composite of ASCVD plus coronary insufficiency, angina pectoris, transient ischemic attack, intermittent claudication, and heart failure) using the Framingham Risk Score measured 2-to-7 years after delivery. These outcomes were assessed as continuous measures of absolute estimated risk in increments of 1%, and, secondarily, as categorical measures with high-risk defined as an estimated probability of CVD >10%. Multivariable linear regression and modified Poisson regression models adjusted for baseline age and individual-level social determinants, including health insurance, educational attainment, and household poverty.

RESULTS

Among 4,309 nulliparous individuals at baseline, the median age was 27 years (IQR: 23-31) and the median ADI was 43 (IQR: 22-74). At 2-to-7 years postpartum (median: 3.1 years, IQR: 2.5, 3.7), the median 30-year risk of ASCVD was 2.3% (IQR: 1.5, 3.5) and of total CVD was 5.5% (IQR: 3.7, 7.9); 2.2% and 14.3% of individuals had predicted 30-year risk >10%, respectively. Individuals living in the highest ADI tertile had a higher predicted risk of 30-year ASCVD % (adj. ß: 0.41; 95% CI: 0.19, 0.63) compared with those in the lowest tertile; and those living in the top two ADI tertiles had higher absolute risks of 30-year total CVD % (T2: adj. ß: 0.37; 95% CI: 0.03, 0.72; T3: adj. ß: 0.74; 95% CI: 0.36, 1.13). Similarly, individuals living in neighborhoods in the highest ADI tertile were more likely to have a high 30-year predicted risk of ASCVD (aRR: 2.21; 95% CI: 1.21, 4.02) and total CVD ≥10% (aRR: 1.35; 95% CI: 1.08, 1.69).

CONCLUSIONS

Neighborhood-level socioeconomic disadvantage in early pregnancy was associated with a higher estimated long-term risk of CVD postpartum. Incorporating aggregated SDOH into existing clinical workflows and future research in pregnancy could reduce disparities in maternal cardiovascular health across the lifespan, and requires further study.

Genetic polymorphisms associated with adverse pregnancy outcomes in nulliparas

Adverse pregnancy outcomes (APOs) affect a large proportion of pregnancies and represent an important cause of morbidity and mortality worldwide. Yet the pathophysiology of APOs is poorly understood, limiting our ability to prevent and treat these conditions. To search for genetic markers of maternal risk for four APOs, we performed multi-ancestry genome-wide association studies (GWAS) for pregnancy loss, gestational length, gestational diabetes, and preeclampsia. We clustered participants by their genetic ancestry and focused our analyses on three sub-cohorts with the largest sample sizes: European, African, and Admixed American. Association tests were carried out separately for each sub-cohort and then meta-analyzed together. Two novel loci were significantly associated with an increased risk of pregnancy loss: a cluster of SNPs located downstream of the TRMU gene (top SNP: rs142795512), and the SNP rs62021480 near RGMA. In the GWAS of gestational length we identified two new variants, rs2550487 and rs58548906 near WFDC1 and AC005052.1, respectively. Lastly, three new loci were significantly associated with gestational diabetes (top SNPs: rs72956265, rs10890563, rs79596863), located on or near ZBTB20, GUCY1A2, and RPL7P20, respectively. Fourteen loci previously correlated with preterm birth, gestational diabetes, and preeclampsia were found to be associated with these outcomes as well.

The Association between Prenatal Nicotine Exposure and Offspring's Hearing Impairment

OBJECTIVES

 The objective of this study is to evaluate whether there is an association between in-utero exposure to nicotine and subsequent hearing dysfunction.

MATERIALS AND METHODS

 Secondary analysis of a multicenter randomized trial to prevent congenital cytomegalovirus (CMV) infection among gravidas with primary CMV infection was conducted. Monthly intravenous immunoglobulin hyperimmune globulin therapy did not influence the rate of congenital CMV. Dyads with missing urine, fetal or neonatal demise, infants diagnosed with a major congenital anomaly, congenital CMV infection, or with evidence of middle ear dysfunction were excluded. The primary outcome was neonatal hearing impairment in one or more ears defined as abnormal distortion product otoacoustic emissions (DPOAEs; 1 to 8 kHz) that were measured within 42 days of birth. DPOAEs were interpreted using optimized frequency-specific level criteria. Cotinine was measured via enzyme-linked immunosorbent assay kits in maternal urine collected at enrollment and in the third trimester (mean gestational age 16.0 and 36.7 weeks, respectively). Blinded personnel ran samples in duplicates. Maternal urine cotinine >5 ng/mL at either time point was defined as in-utero exposure to nicotine. Multivariable logistic regression included variables associated with the primary outcome and with the exposure (p < 0.05) in univariate analysis.

RESULTS

 Of 399 enrolled patients in the original trial, 150 were included in this analysis, of whom 46 (31%) were exposed to nicotine. The primary outcome occurred in 18 (12%) newborns and was higher in nicotine-exposed infants compared with those nonexposed (15.2 vs. 10.6%, odds ratio [OR] 1.52, 95% confidence interval [CI] 0.55-4.20), but the difference was not significantly different (adjusted odds ratio [aOR] = 1.0, 95% CI 0.30-3.31). This association was similar when exposure was stratified as heavy (>100 ng/mL, aOR 0.72, 95% CI 0.15-3.51) or mild (5-100 ng/mL, aOR 1.28, 95% CI 0.33-4.95). There was no association between nicotine exposure and frequency-specific DPOAE amplitude.

CONCLUSION

 In a cohort of parturients with primary CMV infection, nicotine exposure was not associated with offspring hearing dysfunction assessed with DPOAEs.

KEY POINTS

· Nicotine exposure was quantified from maternal urine.. · Nicotine exposure was identified in 30% of the cohort.. · Exposure was not associated with offspring hearing dysfunction..

DLK1: A Novel Biomarker of Placental Insufficiency in Stillbirth and Live Birth

OBJECTIVE

 Delta-like homolog 1 (DLK1) is a growth factor that is reduced in maternal sera in pregnancies with small for gestational age neonates. We sought to determine if DLK1 is associated with stillbirth (SB), with and without placental insufficiency.

STUDY DESIGN

 A nested case-control study was performed using maternal sera from a multicenter case-control study of SB and live birth (LB). SB and LB were stratified as placental insufficiency cases (small for gestational age <5% or circulatory lesions on placental histopathology) or normal placenta controls (appropriate for gestational age and no circulatory lesions). Enzyme-linked immunosorbent assay (ELISA) was used to measure DLK1. The mean difference in DLK1 was compared on the log scale in an adjusted linear regression model with pairwise differences, stratified by term/preterm deliveries among DLK1 results in the quantifiable range. In exploratory analysis, geometric means were compared among all data and the proportion of "low DLK1" (less than the median value for gestational age) was compared between groups and modeled using linear and logistic regression, respectively.

RESULTS

 Overall, 234 SB and 234 LB were analyzed; 246 DLK1 values were quantifiable within the standard curve. Pairwise comparisons of case and control DLK1 geometric means showed no significant differences between groups. In exploratory analysis of all data, adjusted analysis revealed a significant difference for the LB comparison only (SB: 71.9 vs. 99.1 pg/mL, p = 0.097; LB: 37.6 vs. 98.1 pg/mL, p = 0.005). In exploratory analysis of "low DLK1," there was a significant difference between the odds ratio of having "low DLK1" between preterm cases and controls for both SB and LB. There were no significant differences in geometric means nor "low DLK1" between SB and LB.

CONCLUSION

 In exploratory analysis, more placental insufficiency cases in preterm SB and LB had "low DLK1." However, low DLK1 levels were not associated with SB.

KEY POINTS

· Maternally circulating DLK1 is correlated with placental insufficiency.. · Maternally circulating DLK1 is not correlated with SB.. · DLK1 is a promising marker for placental insufficiency..

Association of Maternal Body Mass Index and Maternal Morbidity And Mortality

OBJECTIVE

 This study aimed to assess the association of maternal body mass index (BMI) with a composite of severe maternal outcomes.

STUDY DESIGN

 Secondary analysis of a cohort of deliveries on randomly selected days at 25 hospitals from 2008 to 2011. Data on comorbid conditions, intrapartum events, and postpartum course were collected. The reference group (REF, BMI: 18.5-29.9kg/m2), obese (OB; BMI: 30-39.9kg/m2), morbidly obese (MO; BMI: 40-49.9kg/m2), and super morbidly obese (SMO; BMI ≥ 50kg/m2) women were compared. The composite of severe maternal outcomes was defined as death, intensive care unit (ICU) admission, ventilator use, deep venous thrombosis/pulmonary embolus (DVT/PE), sepsis, hemorrhage, disseminated intravascular coagulation (DIC), unplanned operative procedure, or stroke. Patients in the REF group were matched 1:1 with those in all other obesity groups based on propensity score using the baseline characteristics of age, race/ethnicity, previous cesarean, preexisting diabetes, chronic hypertension, parity, cigarette use, and insurance status. Multivariable Poisson's regression was used to estimate adjusted relative risks (aRRs) and 95% confidence intervals (CIs) for the association between BMI and the composite outcome. Because cesarean delivery may be in the causal pathway between obesity and adverse maternal outcomes, models were then adjusted for mode of delivery to evaluate potential mediation.

RESULTS

 A total of 52,162 pregnant patients are included in the analysis. Risk of composite maternal outcomes was increased for SMO compared with REF but not for OB and MO [OB: aRR=1.06, 95% CI: 0.99-1.14; MO: aRR=1.10, 95% CI: 0.97-1.25; SMO: aRR=1.32, 95% CI: 1.02-1.70]. However, in the mediation analysis, cesarean appears to mediate 46% (95% CI: 31-50%) of the risk of severe morbidity for SMO compared with REF.

CONCLUSION

 Super morbid obesity is significantly associated with increased serious maternal morbidity and mortality; however, cesarean appears to mediate this association. Obesity and morbid obesity are not associated with maternal morbidity and mortality.

KEY POINTS

· Super morbid obesity is associated with increased morbidity.. · Cesarean appears to mediate the association between super morbid obesity and morbidity.. · Obesity and morbid maternal obesity are not associated with morbidity..

Mode of Delivery in Antepartum Singleton Stillbirths and Associated Risk Factors

OBJECTIVE

 This study was aimed to investigate delivery management of patients with antepartum stillbirth.

STUDY DESIGN

 Using data from fetal death certificates and linked maternal hospital discharge records, we identified a population-based sample of patients with singleton antepartum stillbirth at 20 to 42 weeks of gestation in California in 2007 to 2011. Primary outcomes were intended mode of delivery and actual mode of delivery. We used multivariable regressions to examine the association between patient demographic, clinical, and hospital characteristics and their mode of delivery. Separate analysis was performed for patients who had prior cesarean delivery versus those who did not.

RESULTS

 Of 7,813 patients with singleton antepartum stillbirth, 1,356 had prior cesarean, while 6,457 had no prior cesarean. Labor was attempted in 51.8% of patients with prior cesarean and 93.7% of patients without prior cesarean, with 76.2 and 95.8% of these patients, respectively, delivered vaginally. Overall, 18.9% of patients underwent a cesarean delivery (60.5% among those with prior cesarean and 10.2% among those without prior cesarean). Multivariable regression analysis identified several factors associated with the risk of cesarean delivery that were not medically indicated. For instance, among patients without prior cesarean, malpresentation (of which the vast majority was breech presentation) was associated with an increased likelihood of planned cesarean (adjusted odds ratio [OR] = 3.26, 95% confidence interval [CI]: 2.53-4.22) and cesarean delivery after attempting labor (adjusted OR = 3.09, 95% CI: 2.25-4.25). For both patients with and without prior cesarean, delivery at an urban teaching hospital was associated with a lower likelihood of planned cesarean and a lower likelihood of cesarean delivery after attempting labor (adjusted ORs ranged from 0.28 to 0.56, p < 0.001 for all).

CONCLUSION

 Over one in six patients with antepartum stillbirth underwent cesarean delivery. Among patients who attempted labor, rate of vaginal delivery was generally high, suggesting a potential opportunity to increase vaginal delivery in this population.

KEY POINTS

· In singleton antepartum stillbirths, 18.9% underwent cesarean delivery.. · Rate of vaginal delivery was high when labor was attempted.. · Both clinical and non-clinical factors were associated with risk of cesarean delivery..

Does Antenatal Progesterone Administration Modify the Risk of Neonatal Intraventricular Hemorrhage?

OBJECTIVE

 Progesterone administration has been associated with improved neurological outcomes following traumatic brain injury in adults. However, studies examining the effect of progesterone on the risk of neonatal intraventricular hemorrhage (IVH) are inconsistent. We sought to determine if maternal administration of intramuscular 17-α-hydroxyprogesterone caproate (17-OHPC) is associated with decreased rates of IVH in infants born before 32-weeks gestation.

STUDY DESIGN

 This is a retrospective study of liveborn singleton deliveries between 20- and 32-weeks gestation at two large academic medical centers from January 1, 2012 to August 30, 2020. Data were extracted from hospital electronic medical record data warehouses using standardized definitions and billing and diagnosis codes. We evaluated receipt of 17-OHPC in the antepartum period and diagnosis of IVH (grade I-IV, per Volpe classification) during the neonatal delivery hospitalization encounter. Bivariate and multivariate analyses were performed to examine the association between 17-OHPC and neonatal IVH adjusting for potential confounders. Odds ratio (ORs) and 95% confidence intervals (CIs) were presented.

RESULTS

 Among 749 neonates born between 20- and 32-week gestation, 140 (18.7%) of their mothers had received antenatal 17-OHPC and 148 (19.8%) were diagnosed with IVH after birth. No significant association was observed between maternal 17-OHPC and neonatal IVH in unadjusted (OR 1.14, 95% CI 0.72-1.78) or adjusted analyses (adjusted odds ratio 1.14, 95% CI 0.71-1.84). Independent of exposure to 17-OHPC, as expected, infants born <28-weeks gestation or those with very low birthweight (<1,500 g) were at an increased risk of IVH (OR 2.32, 95% CI 1.55-3.48 and OR 2.19, 95% CI 1.09-4.38, respectively).

CONCLUSION

 Antenatal maternal 17-OHPC administration was not associated with the risk of neonatal IVH. Further research may be warranted to determine whether timing, route of delivery, and duration of progesterone therapy impact rates of neonatal IVH.

KEY POINTS

· This study aimed to compare the frequency of intraventricular hemorrhage in preterm neonates exposed to antenatal 17-α-hydroxyprogesterone caproate to those not exposed.. · In neonates born at <32-weeks gestation, maternal use of progesterone is not associated with the risk of intraventricular hemorrhage.. · In contrast to preclinical and adult data, this study suggests that progesterone exposure is not associated with the prevention of neonatal brain injury..

Pregnancy Outcomes in Women Who Developed Elevated Blood Pressure and Stage I Hypertension after 20 Weeks Gestation

OBJECTIVE

 The American College of Obstetrics threshold for hypertension (≥140/90 mm Hg) differs from those of the American College of Cardiology (ACC) and the American Heart Association (AHA). It is unknown if ACC/AHA hypertension levels are associated with adverse pregnancy outcomes (APOs) after 20 weeks gestation. The purpose of this study is to analyze APOs in women with blood pressure (BP) in the elevated or stage 1 range after 20 weeks gestation.

STUDY DESIGN

 This was a secondary analysis of the nuMoM2b prospective cohort study of 10,038 nulliparous, singleton pregnancies between 2010 and 2014. BP was measured at three visits during the pregnancy using a standard protocol. Women without medical comorbidities, with normal BP by ACC/AHA guidelines (systolic BP [SBP] < 120 and diastolic BP [DBP] < 80 mm Hg) up to 22 weeks, were included. Exposure was BP between 22 and 29 weeks gestation: normal (SBP < 120 and DBP < 80 mm Hg), elevated (SBP: 120-129 and DBP < 80 mm Hg), and stage 1 (SBP: 130-139 or DBP: 80-89 mm Hg). The primary outcome was hypertensive disorder of pregnancy (HDP) at delivery. Secondary outcomes included fetal growth restriction (FGR), placental abruption, preterm delivery, and cesarean delivery. Multivariable-adjusted odds ratio (aORs) and 95% confidence intervals (CIs) were estimated using logistic regression models.

RESULTS

 Of 4,460 patients that met inclusion criteria, 3,832 (85.9%) had BP in the normal range, 408 (9.1%) in elevated, and 220 (4.9%) in stage 1 range between 22 and 29 weeks. The likelihood of HDP was significantly higher in women with elevated BP (aOR 1.71, 95%CI: 1.18,2.48), and stage 1 BP (aOR: 2.79, 95%CI: 1.84,4.23) compared to normal BP (p < 0.001). Stage 1 BP had twice odds of FGR (aOR: 2.33, 95%CI: 1.22,4.47) and elevated BP had three times odds of placental abruption (aOR: 3.03; 95%CI: 1.24,7.39).

CONCLUSION

 Elevated or stage 1 BP >20 weeks of pregnancy are associated with HDP, FGR, and placental abruption.

KEY POINTS

· Elevated and stage 1 BP increases risk for HDP.. · Elevated BP increases risk for placental abruption.. · Stage 1 BP increases risk for FGR..

Prediction of Cerebral Palsy or Death among Preterm Infants Who Survive the Neonatal Period

OBJECTIVE

 To assess whether neonatal morbidities evident by the time of hospital discharge are associated with subsequent cerebral palsy (CP) or death.

STUDY DESIGN

 This is a secondary analysis of data from a multicenter placebo-controlled trial of magnesium sulfate for the prevention of CP. The association between prespecified intermediate neonatal outcomes (n = 11) and demographic and clinical factors (n = 10) evident by the time of discharge among surviving infants (n = 1889) and the primary outcome of death or moderate/severe CP at age 2 (n = 73) was estimated, and a prediction model was created.

RESULTS

 Gestational age in weeks at delivery (odds ratio [OR]: 0.74, 95% confidence interval [CI]: 0.67-0.83), grade III or IV intraventricular hemorrhage (IVH) (OR: 5.3, CI: 2.1-13.1), periventricular leukomalacia (PVL) (OR: 46.4, CI: 20.6-104.6), and male gender (OR: 2.5, CI: 1.4-4.5) were associated with death or moderate/severe CP by age 2. Outcomes not significantly associated with the primary outcome included respiratory distress syndrome, bronchopulmonary dysplasia, seizure, necrotizing enterocolitis, neonatal hypotension, 5-minute Apgar score, sepsis, and retinopathy of prematurity. Using all patients, the receiver operating characteristic curve for the final prediction model had an area under the curve of 0.84 (CI: 0.78-0.89). Using these data, the risk of death or developing CP by age 2 can be calculated for individual surviving infants.

CONCLUSION

 IVH and PVL were the only neonatal complications evident at discharge that contributed to an individual infant's risk of the long-term outcomes of death or CP by age 2. A model that includes these morbidities, gestational age at delivery, and gender is predictive of subsequent neurologic sequelae.

KEY POINTS

· Factors known at hospital discharge are identified which are independently associated with death or CP by age 2.. · A model was created and validated using these findings to counsel parents.. · The risk of death or CP can be calculated at the time of hospital discharge..

Prediction of metabolic syndrome following a first pregnancy

BACKGROUND

The prevalence of metabolic syndrome is rapidly increasing in the United States. We hypothesized that prediction models using data obtained during pregnancy can accurately predict the future development of metabolic syndrome.

OBJECTIVE

This study aimed to develop machine learning models to predict the development of metabolic syndrome using factors ascertained in nulliparous pregnant individuals.

STUDY DESIGN

This was a secondary analysis of a prospective cohort study (Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be Heart Health Study [nuMoM2b-HHS]). Data were collected from October 2010 to October 2020, and analyzed from July 2023 to October 2023. Participants had in-person visits 2 to 7 years after their first delivery. The primary outcome was metabolic syndrome, defined by the National Cholesterol Education Program Adult Treatment Panel III criteria, which was measured within 2 to 7 years after delivery. A total of 127 variables that were obtained during pregnancy were evaluated. The data set was randomly split into a training set (70%) and a test set (30%). We developed a random forest model and a lasso regression model using variables obtained during pregnancy. We compared the area under the receiver operating characteristic curve for both models. Using the model with the better area under the receiver operating characteristic curve, we developed models that included fewer variables based on SHAP (SHapley Additive exPlanations) values and compared them with the original model. The final model chosen would have fewer variables and noninferior areas under the receiver operating characteristic curve.

RESULTS

A total of 4225 individuals met the inclusion criteria; the mean (standard deviation) age was 27.0 (5.6) years. Of these, 754 (17.8%) developed metabolic syndrome. The area under the receiver operating characteristic curve of the random forest model was 0.878 (95% confidence interval, 0.846-0.909), which was higher than the 0.850 of the lasso model (95% confidence interval, 0.811-0.888; P<.001). Therefore, random forest models using fewer variables were developed. The random forest model with the top 3 variables (high-density lipoprotein, insulin, and high-sensitivity C-reactive protein) was chosen as the final model because it had the area under the receiver operating characteristic curve of 0.867 (95% confidence interval, 0.839-0.895), which was not inferior to the original model (P=.08). The area under the receiver operating characteristic curve of the final model in the test set was 0.847 (95% confidence interval, 0.821-0.873). An online application of the final model was developed (https://kawakita.shinyapps.io/metabolic/).

CONCLUSION

We developed a model that can accurately predict the development of metabolic syndrome in 2 to 7 years after delivery.

Breastfeeding Initiation, Duration, and Associated Factors Among People With Hepatitis C Virus Infection

OBJECTIVE

To characterize breastfeeding behaviors and identify factors associated with breastfeeding initiation among people with hepatitis C virus (HCV) infection.

METHODS

We conducted a secondary analysis of a multicenter observational cohort of pregnant people with singleton gestations and HCV seropositivity. This analysis includes individuals with data on breastfeeding initiation and excludes those with human immunodeficiency virus (HIV) co-infection. The primary outcome was self-reported initiation of breastfeeding or provision of expressed breast milk. Secondary outcomes included duration of breastfeeding. Demographic and obstetric characteristics were compared between those who initiated breastfeeding and those who did not to identify associated factors. Univariable and multivariable analyses were performed.

RESULTS

Overall, 579 individuals (75.0% of participants in the parent study) were included. Of those, 362 (62.5%) initiated breastfeeding or provided breast milk to their infants, with a median duration of breastfeeding of 1.4 months (interquartile range 0.5-6.0). People with HCV viremia , defined as a detectable viral load at any point during pregnancy, were less likely to initiate breastfeeding than those who had an undetectable viral load (59.4 vs 71.9%, adjusted odds ratio [aOR] 0.61, 95% CI, 0.41-0.92). People with private insurance were more likely to initiate breastfeeding compared with those with public insurance or no insurance (80.0 vs 60.1%; aOR 2.43, 95% CI, 1.31-4.50).

CONCLUSION

Although HCV seropositivity is not a contraindication to breastfeeding regardless of viral load, rates of breastfeeding initiation were lower among people with HCV viremia than among those with an undetectable viral load.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov , NCT01959321 .

Desirability of outcome ranking for obstetrical trials: illustration and application to the ARRIVE trial

BACKGROUND

In randomized trials, 1 primary outcome is typically chosen to evaluate the consequences of an intervention, whereas other important outcomes are relegated to secondary outcomes. This issue is amplified for many obstetrical trials in which an intervention may have consequences for both the pregnant person and the child. In contrast, desirability of outcome ranking, a paradigm shift for the design and analysis of clinical trials based on patient-centric evaluation, allows multiple outcomes-including from >1 individual-to be considered concurrently.

OBJECTIVE

This study aimed to describe desirability of outcome ranking methodology tailored to obstetrical trials and to apply the methodology to maternal-perinatal paired (dyadic) outcomes in which both individuals may be affected by an intervention but may experience discordant outcomes (eg, an obstetrical intervention may improve perinatal but worsen maternal outcomes).

STUDY DESIGN

This secondary analysis applies the desirability of outcome ranking methodology to data from the Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network ARRIVE trial. The original analysis found no substantial difference in the primary (perinatal composite) outcome, but a decreased risk of the secondary outcome of cesarean delivery with elective induction at 39 weeks. In the present desirability-of-outcome-ranking analysis, dyadic outcomes ranging from spontaneous vaginal delivery without severe neonatal complication (most desirable) to cesarean delivery with perinatal death (least desirable) were classified into 8 categories ranked by overall desirability by experienced investigators. Distributions of the desirability of outcome ranking were compared by estimating the probability of having a more desirable dyadic outcome with elective induction at 39 weeks of gestation than with expectant management. To account for various perspectives on these outcomes, a complementary analysis, called the partial credit strategy, was used to grade outcomes on a 100-point scale and estimate the difference in overall treatment scores between groups using a t test.

RESULTS

All 6096 participants from the trial were included. The probability of a better dyadic outcome for a randomly selected patient who was randomized to elective induction was 53% (95% confidence interval, 51-54), implying that elective induction led to a better overall outcome for the dyad when taking multiple outcomes into account concurrently. Furthermore, the desirability-of-outcome-ranking probability of averting cesarean delivery with elective induction was 52% (95% confidence interval, 51-53), which was not at the expense of an operative vaginal delivery or a poorer outcome for the perinate (ie, survival with a severe neonatal complication or perinatal death). Randomization to elective induction was also advantageous in most of the partial credit score scenarios.

CONCLUSION

Desirability-of-outcome-ranking methodology is a useful tool for obstetrical trials because it provides a concurrent view of the effect of an intervention on multiple dyadic outcomes, potentially allowing for better translation of data for decision-making and person-centered care.

Risk Factors, Trends, and Outcomes Associated With Postpartum Sepsis Readmissions

OBJECTIVE

To evaluate the prevalence, timing, clinical risk factors, and adverse outcomes associated with postpartum readmissions for maternal sepsis.

METHODS

We conducted a retrospective cohort study of delivery hospitalizations and 60-day postpartum readmissions for females aged 15-54 years with and without sepsis using the 2016-2020 Nationwide Readmissions Database. Temporal trends in sepsis diagnoses during delivery hospitalizations and 60-day postpartum readmissions were analyzed with the National Cancer Institute's Joinpoint Regression Program to estimate the average annual percent change with 95% CIs. Logistic regression models were fit to determine whether delivery hospitalization characteristics were associated with postpartum sepsis readmissions, and unadjusted and adjusted odds ratios with 95% CIs were reported. Adverse outcomes associated with sepsis during delivery hospitalization and readmission were described, including death, severe morbidity, a critical care composite, and renal failure.

RESULTS

Overall, 15,268,190 delivery hospitalizations and 256,216 associated 60-day readmissions were included after population weighting, of which 16,399 (1.1/1,000 delivery hospitalizations) had an associated diagnosis of sepsis at delivery, and 20,130 (1.3/1,000 delivery hospitalizations) had an associated diagnosis of sepsis with postpartum readmission. A sepsis diagnosis was present in 7.9% of all postpartum readmissions. Characteristics associated with postpartum sepsis readmission included younger age at delivery, Medicaid insurance, lowest median ZIP code income quartile, and chronic medical conditions such as obesity, pregestational diabetes, and chronic hypertension. Postpartum sepsis readmissions were associated with infection during the delivery hospitalization, including intra-amniotic infection or endometritis, wound infection, and delivery sepsis. Sepsis diagnoses were associated with 24.4% of maternal deaths at delivery and 38.4% postpartum, 2.2% cases of nontransfusion severe morbidity excluding sepsis at delivery and 13.6% postpartum, 15.6% of critical care composite diagnoses at delivery and 30.1% postpartum, and 11.1% of acute renal failure diagnoses at delivery and 36.4% postpartum.

CONCLUSION

Sepsis accounts for a significant proportion of postpartum readmissions and is a major contributor to adverse outcomes during delivery hospitalizations and postpartum readmissions.

Infection and Sepsis Trends during United States' Delivery Hospitalizations from 2000 to 2020

OBJECTIVE

 This study aimed to evaluate trends, risk factors, and outcomes associated with infections and sepsis during delivery hospitalizations in the United States.

STUDY DESIGN

 The 2000-2020 National Inpatient Sample was used for this repeated cross-sectional analysis. Delivery hospitalizations of patients aged 15 to 54 with and without infection and sepsis were identified. Common infection diagnoses during delivery hospitalizations analyzed included (i) pyelonephritis, (ii) pneumonia/influenza, (iii) endometritis, (iv) cholecystitis, (v) chorioamnionitis, and (vi) wound infection. Temporal trends in sepsis and infection during delivery hospitalizations were analyzed. The associations between sepsis and infection and common chronic health conditions including asthma, chronic hypertension, pregestational diabetes, and obesity were analyzed. The associations between clinical, demographic, and hospital characteristics, and infection and sepsis were determined with unadjusted and adjusted logistic regression models with unadjusted odds ratio (OR) and adjusted odds ratios with 95% confidence intervals as measures of association.

RESULTS

 An estimated 80,158,622 delivery hospitalizations were identified and included in the analysis, of which 2,766,947 (3.5%) had an infection diagnosis and 32,614 had a sepsis diagnosis (4.1 per 10,000). The most common infection diagnosis was chorioamnionitis (2.7% of deliveries) followed by endometritis (0.4%), and wound infections (0.3%). Infection and sepsis were more common in the setting of chronic health conditions. Evaluating trends in individual infection diagnoses, endometritis and wound infection decreased over the study period both for patients with and without chronic conditions, while risk for pyelonephritis and pneumonia/influenza increased. Sepsis increased over the study period for deliveries with and without chronic condition diagnoses. Risks for adverse outcomes including mortality, severe maternal morbidity, the critical care composite, and acute renal failure were all significantly increased in the presence of sepsis and infection.

CONCLUSION

 Endometritis and wound infections decreased over the study period while risk for sepsis increased. Infection and sepsis were associated with chronic health conditions and accounted for a significant proportion of adverse obstetric outcomes including severe maternal morbidity.

KEY POINTS

· Sepsis increased over the study period for deliveries with and without chronic condition diagnoses.. · Endometritis and wound infection decreased over the study period.. · Infection and sepsis accounted for a significant proportion of adverse obstetric outcomes..

Postpartum readmission risk: a comparison between stillbirths and live births

BACKGROUND

Stillbirth occurs more commonly among pregnant people with comorbid conditions and obstetrical complications. Stillbirth also independently increases maternal morbidity and imparts a psychosocial hazard when compared with live birth. These distinct needs and burden may increase the risk for postpartum readmission after stillbirth.

OBJECTIVE

This study aimed to examine the risk for maternal postpartum readmission after stillbirth in comparison with live birth and to identify indications for readmission and the associated risk factors.

STUDY DESIGN

This was a retrospective cohort of patients with singleton stillbirths or live births, delivered at ≥20 weeks' gestation, who were identified from the 2019 Nationwide Readmissions Database. The primary outcome was all-cause readmission within 6 weeks of discharge from the childbirth hospitalization. The association between stillbirth (vs live birth) and risk for readmission was assessed using multivariable regression models with adjustment for maternal age, sociodemographic characteristics, maternal and obstetrical conditions, and delivery characteristics. Within the stillbirth group, risk factors for readmission were further examined using multivariable regression. The secondary outcomes included principal indication for readmission (categorized based on principal diagnosis code of the readmission hospitalization) and timing of readmission (number of weeks after childbirth hospitalization). Differences in these secondary outcomes were compared between the stillbirth and live birth groups using chi-square tests. All analyses accounted for the complex sample design to generate nationally representative estimates.

RESULTS

Postpartum readmission occurred in 2.7% of 16,636 patients with stillbirths, whereas it occurred in 1.6% of 2,870,677 patients with live births (unadjusted risk ratio, 1.65; 95% confidence interval, 1.47-1.86). The higher risk for readmission after stillbirth (vs live birth) persisted after adjusting for maternal, obstetrical, and delivery characteristics (adjusted risk ratio, 1.27; 95% confidence interval, 1.11-1.46). The distribution of principal indication for readmission differed after stillbirth and after live birth and included hypertension (30.2% vs 39.5%; unadjusted risk ratio, 0.76; 95% confidence interval, 0.63-0.93), mental health or substance use disorders (6.8% vs 3.6%; unadjusted risk ratio, 1.90; 95% confidence interval, 1.15-3.16), and venous thromboembolism (5.8% vs 2.0%; unadjusted risk ratio, 2.87; 95% confidence interval, 1.60-5.17). Among patients with stillbirths, 56.0% of readmissions occurred within 1 week, 71.8% within 2 weeks, and 88.1% within 4 weeks; the timing of readmission did not differ significantly between the stillbirth and live birth cohorts. Pregestational diabetes (adjusted risk ratio, 1.87; 95% confidence interval, 1.20-2.93), gestational diabetes (adjusted risk ratio, 1.67; 95% confidence interval, 1.03-2.71), hypertensive disorders of pregnancy (adjusted risk ratio, 1.80; 95% confidence interval, 1.31-2.47), obesity (adjusted risk ratio, 1.46; 95% confidence interval, 1.01-2.12), and primary cesarean delivery (adjusted risk ratio, 1.74; 95% confidence interval, 1.17-2.58) were associated with a higher risk for readmission after stillbirth, whereas higher household income was associated with a lower risk for readmission (eg, adjusted risk ratio for income ≥$82,000 vs $1-$47,999, 0.48; 95% confidence interval, 0.30-0.77).

CONCLUSION

When compared with live births, the risk for postpartum readmission was higher after stillbirths, even after adjustment for differences in the patient demographic and clinical characteristics. Readmission for mental health or substance use disorders and venous thromboembolism is more common after stillbirths than after live births.

Association of Mild Iodine Insufficiency during Pregnancy with Child Neurodevelopment in Patients with Subclinical Hypothyroidism or Hypothyroxinemia

OBJECTIVE

 Our objective was to evaluate whether iodine status in pregnant patients with either subclinical hypothyroidism or hypothyroxinemia in the first half of pregnancy is associated with measures of behavior and neurodevelopment in children through the age of 5 years.

STUDY DESIGN

 This is a secondary analysis of a multicenter study consisting of two randomized, double-masked, placebo-controlled treatment trials conducted in parallel. Patients with a singleton gestation before 20 weeks' gestation underwent thyroid screening using serum thyrotropin and free thyroxine. Participants with subclinical hypothyroidism or hypothyroxinemia were randomized to levothyroxine replacement or an identical placebo. At randomization, maternal urine was collected and stored for subsequent urinary iodine excretion analysis. Urinary iodine concentrations greater than 150 μg/L were considered iodine sufficient, and concentrations of 150 μg/L or less were considered iodine insufficient. The primary outcome was a full-scale intelligence quotient (IQ) score at the age of 5 years, the general conceptual ability score from the Differential Ability Scales-II at the age of 3 if IQ was not available, or death before 3 years.

RESULTS

 A total of 677 pregnant participants with subclinical hypothyroidism and 526 with hypothyroxinemia were randomized. The primary outcome was available in 1,133 (94%) of children. Overall, 684 (60%) of mothers were found to have urinary iodine concentrations >150 μg/L. Children of iodine-sufficient participants with subclinical hypothyroidism had similar primary outcome scores when compared to children of iodine-insufficient participants (95 [84-105] vs. 96 [87-109], P adj = 0.73). After adjustment, there was also no difference in IQ scores among children of participants with hypothyroxinemia at 5 to 7 years of age (94 [85 - 102] and 91 [81 - 100], Padj 1/4 0.11). Treatment with levothyroxine was not associated with neurodevelopmental or behavioral outcomes regardless of maternal iodine status (p > 0.05).

CONCLUSION

 Maternal urinary iodine concentrations ≤150 μg/L were not associated with abnormal cognitive or behavioral outcomes in offspring of participants with either subclinical hypothyroidism or hypothyroxinemia.

KEY POINTS

· Most pregnant patients with subclinical thyroid disease are iodine sufficient.. · Mild maternal iodine insufficiency is not associated with lower offspring IQ at 5 years.. · Iodine supplementation in subclinical thyroid disease is unlikely to improve IQ..

Copy number variants and fetal structural abnormalities in stillborn fetuses: A secondary analysis of the Stillbirth Collaborative Research Network study

OBJECTIVE

To examine the association of placental and fetal DNA copy number variants (CNVs) with fetal structural malformations (FSMs) in stillborn fetuses.

DESIGN

A secondary analysis of stillbirth cases in the Stillbirth Collaborative Research Network (SCRN) study.

SETTING

Multicenter, 59 hospitals in five geographic regions in the USA.

POPULATION

388 stillbirth cases of the SCRN study (2006-2008).

METHODS

Fetal structural malformations were grouped by anatomic system and specific malformation type (e.g. central nervous system, thoracic, cardiac, gastrointestinal, skeletal, umbilical cord and craniofacial defects). Single-nucleotide polymorphism array detected CNVs of at least 500 kb. CNVs were classified into two groups: normal, defined as no CNVs >500 kb or benign CNVs, and abnormal, defined as pathogenic or variants of unknown clinical significance.

MAIN OUTCOME MEASURES

The proportions of abnormal CNVs and normal CNVs were compared between stillbirth cases with and without FSMs using the Wald Chi-square test.

RESULTS

The proportion of stillbirth cases with any FSMs was higher among those with abnormal CNVs than among those with normal CNVs (47.5 versus 19.1%; P-value <0.001). The most common organ system-specific FSMs associated with abnormal CNVs were cardiac defects, followed by hydrops, craniofacial defects and skeletal defects. A pathogenic deletion of 1q21.1 involving 46 genes (e.g. CHD1L) and a duplication of 21q22.13 involving four genes (SIM2, CLDN14, CHAF1B, HLCS) were associated with a skeletal and cardiac defect, respectively.

CONCLUSION

Specific CNVs involving several genes were associated with FSMs in stillborn fetuses. The findings warrant further investigation and may inform counselling and care surrounding pregnancies affected by FSMs at risk for stillbirth.

Fetal Tachycardia in the Setting of Maternal Intrapartum Fever and Perinatal Morbidity

OBJECTIVE

 The fetal consequences of intrapartum fetal tachycardia with maternal fever or clinical chorioamnionitis are not well studied. We evaluated the association between perinatal morbidity and fetal tachycardia in the setting of intrapartum fever.

STUDY DESIGN

 Secondary analysis of a multicenter randomized control trial that enrolled 5,341 healthy laboring nulliparous women ≥36 weeks' gestation. Women with intrapartum fever ≥ 38.0°C (including those meeting criteria for clinical chorioamnionitis) after randomization were included in this analysis. Isolated fetal tachycardia was defined as fetal heart rate (FHR) ≥160 beats per minute for at least 10 minutes in the absence of other FHR abnormalities. FHR abnormalities other than tachycardia were excluded from the analysis. The primary outcome was a perinatal composite (5-minute Apgar's score ≤3, intubation, chest compressions, or mortality). Secondary outcomes included low arterial cord pH (pH < 7.20), base deficit ≥12, and cesarean delivery.

RESULTS

 A total of 986 (18.5%) of women in the trial developed intrapartum fever, and 728 (13.7%) met criteria to be analyzed; of these, 728 women 336 (46.2%) had maternal-fetal medicine (MFM) reviewer-defined fetal tachycardia, and 349 of the 550 (63.5%) women during the final hour of labor had validated software (PeriCALM) defined fetal tachycardia. After adjusting for confounders, isolated fetal tachycardia was not associated with a significant difference in the composite perinatal outcome (adjusted odds ratio [aOR] = 3.15 [0.82-12.03]) compared with absence of tachycardia. Fetal tachycardia was associated with higher odds of arterial cord pH <7.2, aOR = 1.48 (1.01-2.17) and of infants with a base deficit ≥ 12, aOR = 2.42 (1.02-5.77), but no significant difference in the odds of cesarean delivery, aOR = 1.33 (0.97-1.82).

CONCLUSION

 Fetal tachycardia in the setting of intrapartum fever or chorioamnionitis is associated with significantly increased fetal acidemia defined as a pH <7.2 and base excess ≥12 but not with a composite perinatal morbidity.

KEY POINTS

· The perinatal outcomes associated with fetal tachycardia in the setting of maternal fever are undefined.. · Fetal tachycardia was not significantly associated with perinatal morbidity although the sample size was limited.. · Fetal tachycardia was associated with an arterial cord pH <7.2 and base deficit of 12 or greater..

Comparing population-based fetal growth standards in a US cohort

BACKGROUND

No fetal growth standard is currently endorsed for universal use in the United States. Newer standards improve upon the methodologic limitations of older studies; however, before adopting into practice, it is important to know how recent standards perform at identifying fetal undergrowth or overgrowth and at predicting subsequent neonatal morbidity or mortality in US populations.

OBJECTIVE

To compare classification of estimated fetal weight that is <5th or 10th percentile or >90th percentile by 6 population-based fetal growth standards and the ability of these standards to predict a composite of neonatal morbidity and mortality.

STUDY DESIGN

We used data from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-be cohort, which recruited nulliparous women in the first trimester at 8 US clinical centers (2010-2014). Estimated fetal weight was obtained from ultrasounds at 16 to 21 and 22 to 29 weeks of gestation (N=9534 women). We calculated rates of fetal growth restriction (estimated fetal weight <5th and 10th percentiles; fetal growth restriction<5 and fetal growth restriction<10) and estimated fetal weight >90th percentile (estimated fetal weight>90) from 3 large prospective fetal growth cohorts with similar rigorous methodologies: INTERGROWTH-21, World Health Organization-sex-specific and combined, Eunice Kennedy Shriver National Institute of Child Health and Human Development race-ethnic-specific and unified, and the historic Hadlock reference. To determine whether differential classification of fetal growth restriction or estimated fetal weight >90 among standards was clinically meaningful, we then compared area under the curve and sensitivity of each standard to predict small for gestational age or large for gestational age at birth, composite perinatal morbidity and mortality alone, and small for gestational age or large for gestational age with composite perinatal morbidity and mortality.

RESULTS

The standards classified different proportions of fetal growth restriction and estimated fetal weight>90 for ultrasounds at 16 to 21 (visit 2) and 22 to 29 (visit 3) weeks of gestation. At visit 2, the Eunice Kennedy Shriver National Institute of Child Health and Human Development race-ethnic-specific, World Health Organization sex-specific and World Health Organization-combined identified similar rates of fetal growth restriction<10 (8.4%-8.5%) with the other 2 having lower rates, whereas Eunice Kennedy Shriver National Institute of Child Health and Human Development race-ethnic-specific identified the highest rate of fetal growth restriction<5 (5.0%) compared with the other references. At visit 3, World Health Organization sex-specific classified 9.2% of fetuses as fetal growth restriction<10, whereas the other 5 classified a lower proportion as follows: World Health Organization-combined (8.4%), Eunice Kennedy Shriver National Institute of Child Health and Human Development race-ethnic-specific (7.7%), INTERGROWTH (6.2%), Hadlock (6.1%), and Eunice Kennedy Shriver National Institute of Child Health and Human Development unified (5.1%). INTERGROWTH classified the highest (21.3%) as estimated fetal weight>90 whereas Hadlock classified the lowest (8.3%). When predicting composite perinatal morbidity and mortality in the setting of early-onset fetal growth restriction, World Health Organization had the highest area under the curve of 0.53 (95% confidence interval, 0.51-0.53) for fetal growth restriction<10 at 22 to 29 weeks of gestation, but the areas under the curve were similar among standards (0.52). Sensitivity was generally low across standards (22.7%-29.1%). When predicting small for gestational age birthweight with composite neonatal morbidity or mortality, for fetal growth restriction<10 at 22 to 29 weeks of gestation, World Health Organization sex-specific had the highest area under the curve (0.64; 95% confidence interval, 0.60-0.67) and INTERGROWTH had the lowest (area under the curve=0.58; 95% confidence interval 0.55-0.62), though all standards had low sensitivity (7.0%-9.6%).

CONCLUSION

Despite classifying different proportions of fetuses as fetal growth restriction or estimated fetal weight>90, all standards performed similarly in predicting perinatal morbidity and mortality. Classification of different percentages of fetuses as fetal growth restriction or estimated fetal weight>90 among references may have clinical implications in the management of pregnancies, such as increased antenatal monitoring for fetal growth restriction or cesarean delivery for suspected large for gestational age. Our findings highlight the importance of knowing how standards perform in local populations, but more research is needed to determine if any standard performs better at identifying the risk of morbidity or mortality.

Researching COVID to enhance recovery (RECOVER) pregnancy study: Rationale, objectives and design

IMPORTANCE

Pregnancy induces unique physiologic changes to the immune response and hormonal changes leading to plausible differences in the risk of developing post-acute sequelae of SARS-CoV-2 (PASC), or Long COVID. Exposure to SARS-CoV-2 during pregnancy may also have long-term ramifications for exposed offspring, and it is critical to evaluate the health outcomes of exposed children. The National Institutes of Health (NIH) Researching COVID to Enhance Recovery (RECOVER) Multi-site Observational Study of PASC aims to evaluate the long-term sequelae of SARS-CoV-2 infection in various populations. RECOVER-Pregnancy was designed specifically to address long-term outcomes in maternal-child dyads.

METHODS

RECOVER-Pregnancy cohort is a combined prospective and retrospective cohort that proposes to enroll 2,300 individuals with a pregnancy during the COVID-19 pandemic and their offspring exposed and unexposed in utero, including single and multiple gestations. Enrollment will occur both in person at 27 sites through the Eunice Kennedy Shriver National Institutes of Health Maternal-Fetal Medicine Units Network and remotely through national recruitment by the study team at the University of California San Francisco (UCSF). Adults with and without SARS-CoV-2 infection during pregnancy are eligible for enrollment in the pregnancy cohort and will follow the protocol for RECOVER-Adult including validated screening tools, laboratory analyses and symptom questionnaires followed by more in-depth phenotyping of PASC on a subset of the overall cohort. Offspring exposed and unexposed in utero to SARS-CoV-2 maternal infection will undergo screening tests for neurodevelopment and other health outcomes at 12, 18, 24, 36 and 48 months of age. Blood specimens will be collected at 24 months of age for SARS-CoV-2 antibody testing, storage and anticipated later analyses proposed by RECOVER and other investigators.

DISCUSSION

RECOVER-Pregnancy will address whether having SARS-CoV-2 during pregnancy modifies the risk factors, prevalence, and phenotype of PASC. The pregnancy cohort will also establish whether there are increased risks of adverse long-term outcomes among children exposed in utero.

CLINICAL TRIALS.GOV IDENTIFIER

Clinical Trial Registration: http://www.clinicaltrials.gov. Unique identifier: NCT05172011.

Cannabis Exposure and Adverse Pregnancy Outcomes Related to Placental Function

Importance

Cannabis use is increasing among reproductive-age individuals and the risks associated with cannabis exposure during pregnancy remain uncertain.

Objective

To evaluate the association between maternal cannabis use and adverse pregnancy outcomes known to be related to placental function.

Design, Setting, and Participants

Ancillary analysis of nulliparous individuals treated at 8 US medical centers with stored urine samples and abstracted pregnancy outcome data available. Participants in the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be cohort were recruited from 2010 through 2013; the drug assays and analyses for this ancillary project were completed from June 2020 through April 2023.

Exposure

Cannabis exposure was ascertained by urine immunoassay for 11-nor-9-carboxy-Δ9-tetrahydrocannabinol using frozen stored urine samples from study visits during the pregnancy gestational age windows of 6 weeks and 0 days to 13 weeks and 6 days (visit 1); 16 weeks and 0 days to 21 weeks and 6 days (visit 2); and 22 weeks and 0 days to 29 weeks and 6 days (visit 3). Positive results were confirmed with liquid chromatography tandem mass spectrometry. The timing of cannabis exposure was defined as only during the first trimester or ongoing exposure beyond the first trimester.

Main Outcome and Measure

The dichotomous primary composite outcome included small-for-gestational-age birth, medically indicated preterm birth, stillbirth, or hypertensive disorders of pregnancy ascertained by medical record abstraction by trained perinatal research staff with adjudication of outcomes by site investigators.

Results

Of 10 038 participants, 9257 were eligible for this analysis. Of the 610 participants (6.6%) with cannabis use, 32.4% (n = 197) had cannabis exposure only during the first trimester and 67.6% (n = 413) had ongoing exposure beyond the first trimester. Cannabis exposure was associated with the primary composite outcome (25.9% in the cannabis exposure group vs 17.4% in the no exposure group; adjusted relative risk, 1.27 [95% CI, 1.07-1.49]) in the propensity score-weighted analyses after adjustment for sociodemographic characteristics, body mass index, medical comorbidities, and active nicotine use ascertained via urine cotinine assays. In a 3-category cannabis exposure model (no exposure, exposure only during the first trimester, or ongoing exposure), cannabis use during the first trimester only was not associated with the primary composite outcome; however, ongoing cannabis use was associated with the primary composite outcome (adjusted relative risk, 1.32 [95% CI, 1.09-1.60]).

Conclusions and Relevance

In this multicenter cohort, maternal cannabis use ascertained by biological sampling was associated with adverse pregnancy outcomes related to placental dysfunction.

Oral Glucose Tolerance Test in Pregnancy and Subsequent Maternal Hypertension

OBJECTIVE

The aim of the study is to evaluate whether values and the shape of the glucose curve during the oral glucose tolerance test (OGTT) in pregnancy identify women at risk of developing hypertension (HTN) later in life.

STUDY DESIGN

This category includes the secondary analysis of a follow-up from a mild gestational diabetes mellitus (GDM) study that included a treatment trial for mild GDM (n = 458) and an observational cohort of participants with abnormal 1-hour glucose loading test only (normal OGTT, n = 430). Participants were assessed at a median of 7 (IQR 6-8) years after their index pregnancy, and trained staff measured their blood pressure (systolic blood pressure [SBP]; diastolic blood pressure [DBP]). The association between values and the shape of the glucose curve during OGTT in the index pregnancy and the primary outcome defined as elevated BP (SBP ≥120, DBP ≥80 mm Hg, or receiving anti-HTN medications), and secondary outcome defined as stage 1 or higher (SBP ≥130, DBP ≥80 mm Hg, or receiving anti-HTN medications) at follow-up were evaluated using multivariable regression, adjusting for maternal age, body mass index, and pregnancy-associated hypertension during the index pregnancy.

RESULTS

There was no association between fasting, 1-hour OGTT, and the outcomes. However, the 2-hour OGTT value was positively associated (adjusted odds ratio [aRR] per 10-unit increase 1.04, 95% CI 1.01-1.08), and the 3-hour was inversely associated (aRR per 10-unit increase 0.96, 95% CI 0.93-0.99) with the primary outcome. When the shape of the OGTT curve was evaluated, a monophasic OGTT response (peak at 1 hour followed by a decline in glucose) was associated with increased risk of elevated BP (41.3vs. 23.5%, aRR 1.66, 95% CI 1.17-2.35) and stage 1 HTN or higher (28.5 vs. 14.7%, aRR 1.83, 95% CI 1.15-2.92), compared with a biphasic OGTT response.

CONCLUSION

Among persons with mild GDM or lesser degrees of glucose intolerance, the shape of the OGTT curve during pregnancy may help identify women who are at risk of HTN later in life, with biphasic shape to be associated with lower risk.

KEY POINTS

· The shape of the Oral Glucose Tolerance Test curve may help identify patients who are at risk of having elevated BP or HTN 5 to 10 years following pregnancy.. · The 2-hour Oral Glucose Tolerance Test values is positively associated with elevated BP 5 to 10 years following pregnancy.. · This supports the concept of pregnancy as a window to future health and represents a potential novel biomarker for maternal cardiovascular health screening..

Assessing Intrauterine Retention according to Microscopic Stillbirth Features: A Cluster Analysis Approach

Background: Previous studies identified microscopic changes associated with intrauterine retention of stillbirths based on clinical time of death. The objective of this study was to utilize unsupervised machine learning (not reliant on subjective measures) to identify features associated with time from death to delivery. Methods: Data were derived from the Stillbirth Collaborative Research Network. Features were chosen a priori for entry into hierarchical cluster analysis, including fetal and placental changes. Results: A four-cluster solution (coefficient = 0.983) correlated with relative time periods of "no retention," "mild retention," "moderate retention," and "severe retention." Loss of nuclear basophilia within fetal organs were found at varying rates among these clusters. Conclusions: Hierarchical cluster analysis is able to classify stillbirths based on histopathological changes, roughly correlating to length of intrauterine retention. Such clusters, which rely solely on objective fetal and placental findings, can help clinicians more accurately assess the interval from death to delivery.

Fetal growth restriction and small for gestational age as predictors of neonatal morbidity: which growth nomogram to use?

BACKGROUND

Fetal growth nomograms were developed to screen for fetal growth restriction and guide clinical care to improve perinatal outcomes; however, existing literature remains inconclusive regarding which nomogram is the gold standard.

OBJECTIVE

This study aimed to compare the ability of 4 commonly used nomograms (Hadlock, International Fetal and Newborn Growth Consortium for the 21st Century, Eunice Kennedy Shriver National Institute of Child Health and Human Development-unified standard, and World Health Organization fetal growth charts) and 1 institution-specific reference to predict small for gestational age and poor neonatal outcomes.

STUDY DESIGN

This was a retrospective cohort study of all nonanomalous singleton pregnancies undergoing ultrasound at ≥20 weeks of gestation between 2013 and 2020 and delivering at a single academic center. Using random selection methods, the study sample was restricted to 1 pregnancy per patient and 1 ultrasound per pregnancy completed at ≥22 weeks of gestation. Fetal biometry data were used to calculate estimated fetal weight and percentiles according to the aforementioned 5 nomograms. Maternal and neonatal data were extracted from electronic medical records. Logistic regression was used to estimate the association between estimated fetal weight of <10th and <3rd percentiles compared with estimated fetal weight of 10th to 90th percentile as the reference group for small for gestational age and the neonatal composite outcomes (perinatal mortality, hypoxic-ischemic encephalopathy or seizures, respiratory morbidity, intraventricular hemorrhage, necrotizing enterocolitis, hyperbilirubinemia or hypoglycemia requiring neonatal intensive care unit admission, and retinopathy of prematurity). Receiver operating characteristic curve contrast estimation (primary analysis) and test characteristics were calculated for all nomograms and the prediction of small for gestational age and the neonatal composite outcomes. We restricted the sample to ultrasounds performed within 28 days of delivery; moreover, similar analyses were completed to assess the prediction of small for gestational age and neonatal composite outcomes.

RESULTS

Among 10,045 participants, the proportion of fetuses classified as <10th percentile varied across nomograms from 4.9% to 9.7%. Fetuses with an estimated fetal weight of <10th percentile had an increased risk of small for gestational age (odds ratio, 9.9 [95% confidence interval, 8.5-11.5] to 12.8 [95% confidence interval, 10.9-15.0]). In addition, the estimated fetal weight of <10th and <3rd percentile was associated with increased risk of the neonatal composite outcome (odds ratio, 2.4 [95% confidence interval, 2.0-2.8] to 3.5 [95% confidence interval, 2.9-4.3] and 5.7 [95% confidence interval, 4.5-7.2] to 8.8 [95% confidence interval, 6.6-11.8], respectively). The prediction of small for gestational age with an estimated fetal weight of <10th percentile had a positive likelihood ratio of 6.3 to 8.5 and an area under the curve of 0.62 to 0.67. Similarly, the prediction of the neonatal composite outcome with an estimated fetal weight of <10th percentile had a positive likelihood ratio of 2.1 to 3.1 and an area under the curve of 0.55 to 0.57. When analyses were restricted to ultrasound within 4 weeks of delivery, among fetuses with an estimated fetal weight of <10th percentile, the risk of small for gestational age increased across all nomograms (odds ratio, 16.7 [95% confidence interval, 12.6-22.3] to 25.1 [95% confidence interval, 17.0-37.0]), and prediction improved (positive likelihood ratio, 8.3-15.0; area under the curve, 0.69-0.75). Similarly, the risk of neonatal composite outcome increased (odds ratio, 3.2 [95% confidence interval, 2.4-4.2] to 5.2 [95% confidence interval, 3.8-7.2]), and prediction marginally improved (positive likelihood ratio, 2.4-4.1; area under the curve, 0.60-0.62). Importantly, the risk of both being small for gestational age and having the neonatal composite outcome further increased (odds ratio, 21.4 [95% confidence interval, 13.6-33.6] to 28.7 (95% confidence interval, 18.6-44.3]), and the prediction of concurrent small for gestational age and neonatal composite outcome greatly improved (positive likelihood ratio, 6.0-10.0; area under the curve, 0.80-0.83).

CONCLUSION

In this large cohort, Hadlock, recent fetal growth nomograms, and a local population-derived fetal growth reference performed comparably in the prediction of small for gestational age and neonatal composite outcomes.

Perinatal Outcomes Associated With Management of Stage 1 Hypertension

OBJECTIVE

To evaluate the association between maternal blood pressure (BP) below 130/80 mm Hg compared with 130-139/80-89 mm Hg and pregnancy outcomes.

METHODS

We conducted a planned secondary analysis of CHAP (Chronic Hypertension and Pregnancy), an open label, multicenter, randomized controlled trial. Participants with mean BP below 140/90 mm Hg were grouped as below 130/80 mm Hg compared with 130-139/80-89 mm Hg by averaging postrandomization clinic BP throughout pregnancy. The primary composite outcome was preeclampsia with severe features, indicated preterm birth before 35 weeks of gestation, placental abruption, or fetal or neonatal death. The secondary outcome was small for gestational age (SGA).

RESULTS

Of 2,408 patients in CHAP, 2,096 met study criteria; 1,328 had mean BP 130-139/80-89 mm Hg and 768 had mean BP below 130/80 mm Hg. Participants with mean BP below 130/80 mm Hg were more likely to be older, on antihypertensive medication, in the active treatment arm, and to have lower BP at enrollment. Mean clinic BP below 130/80 mm Hg was associated with lower frequency of the primary outcome (16.0% vs 35.8%, adjusted relative risk 0.45; 95% CI 0.38-0.54) as well as lower risk of severe preeclampsia and indicated birth before 35 weeks of gestation. There was no association with SGA.

CONCLUSION

In pregnant patients with mild chronic hypertension, mean BP below 130/80 mm Hg was associated with improved pregnancy outcomes without increased risk of SGA.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov , NCT02299414.

Neighborhood Socioeconomic Disadvantage and Abnormal Birth Weight

OBJECTIVE

To examine whether exposure to community or neighborhood socioeconomic disadvantage as measured by the ADI (Area Deprivation Index) is associated with risk of abnormal birth weight among nulliparous individuals with singleton gestations.

METHODS

This was a secondary analysis from the prospective cohort NuMoM2b study (Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-To-Be). Participant addresses at cohort enrollment between 6 and 13 weeks of gestation were geocoded at the Census tract level and linked to the 2015 ADI. The ADI, which incorporates the domains of income, education, employment, and housing quality into a composite national ranking of neighborhood socioeconomic disadvantage, was categorized by quartiles (quartile 1, least disadvantaged, reference; quartile 4, most disadvantaged). Outcomes were large for gestational age (LGA; birth weight at or above the 90th percentile) and small for gestational age (SGA; birth weight below the 10th percentile) compared with appropriate for gestational age (AGA; birth weight 10th-90th percentile) as determined with the 2017 U.S. natality reference data, standardized for fetal sex. Multinomial logistic regression models were adjusted for potential confounding variables.

RESULTS

Of 8,983 assessed deliveries in the analytic population, 12.7% (n=1,143) were SGA, 8.2% (n=738) were LGA, and 79.1% (n=7,102) were AGA. Pregnant individuals living in the highest ADI quartile (quartile 4, 17.8%) had an increased odds of delivering an SGA neonate compared with those in the lowest referent quartile (quartile 1, 12.4%) (adjusted odds ratio [aOR] 1.32, 95% CI 1.09-1.55). Pregnant individuals living in higher ADI quartiles (quartile 2, 10.3%; quartile 3, 10.7%; quartile 4, 9.2%) had an increased odds of delivering an LGA neonate compared with those in the lowest referent quartile (quartile 1, 8.2%) (aOR: quartile 2, 1.40, 95% CI 1.19-1.61; quartile 3, 1.35, 95% CI 1.09-1.61; quartile 4, 1.47, 95% CI 1.20-1.74).

CONCLUSION

Neonates of nulliparous pregnant individuals living in U.S. neighborhoods with higher area deprivation were more likely to have abnormal birth weights at both extremes.

Searching and visualizing genetic associations of pregnancy traits by using GnuMoM2b

Adverse pregnancy outcomes (APOs) are major risk factors for women's health during pregnancy and even in the years after pregnancy. Due to the heterogeneity of APOs, only few genetic associations have been identified. In this report, we conducted genome-wide association studies (GWASs) of 479 traits that are possibly related to APOs using a large and racially diverse study, Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b). To display extensive results, we developed a web-based tool GnuMoM2b (https://gnumom2b.cumcobgyn.org/) for searching, visualizing, and sharing results from a GWAS of 479 pregnancy traits as well as phenome-wide association studies of more than 17 million single nucleotide polymorphisms. The genetic results from 3 ancestries (Europeans, Africans, and Admixed Americans) and meta-analyses are populated in GnuMoM2b. In conclusion, GnuMoM2b is a valuable resource for extraction of pregnancy-related genetic results and shows the potential to facilitate meaningful discoveries.

Risk factors and perinatal outcomes for persistent placenta previa in nulliparas

BACKGROUND

Placenta previa diagnosed on midtrimester ultrasound often resolves by the third trimester. Multiparity and previous cesarean delivery have been associated with persistence of placenta previa at delivery. Risk factors for persistent placenta previa in nulliparas are not well characterized.

OBJECTIVE

This study aimed to identify risk factors for persistent placenta previa in the nulliparous population, and evaluate differences in outcomes between persistent and resolved placenta previa.

STUDY DESIGN

This was a secondary analysis of the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-be (nuMoM2b), a prospective cohort study that observed 10,037 nulliparous individuals throughout pregnancy. Nulliparas diagnosed with placenta previa on midtrimester ultrasound were included in this analysis. Baseline characteristics and delivery outcomes of nulliparas with persistent placenta previa were compared with those of nulliparas with resolved placenta previa. Multivariate logistic regression with stepwise model selection was used for adjusted analyses.

RESULTS

A total of 171 nulliparas (1.7%) in the nuMoM2b study were diagnosed with placenta previa on midtrimester ultrasound, of whom 17% (n=29) had persistent placenta previa at delivery. When compared with those with resolved placenta previa, nulliparas with persistent placenta previa were more likely to be older (median, 32 years [interquartile range, 30-37] vs 29 years [interquartile range, 25-31]; P<.01), have a previous pregnancy of <20 weeks (48.3% vs 22.5%; P=.01), have a previous dilation and curettage/evacuation procedure (27.6% vs 10.6%; P=.03), or have a pregnancy that resulted from assisted reproductive technology (31% vs 4.9%; P=.01). After adjusting for potential confounders, maternal age (adjusted odds ratio, 1.11; 95% confidence interval, 1.02-1.21), in vitro fertilization (adjusted odds ratio, 9.00; 95% confidence interval, 1.97-41.14), and previous pregnancy of <20 weeks (adjusted odds ratio, 2.77; 95% confidence interval, 1.10-6.95) remained statistically significant risk factors for persistent placenta previa. Persistent placenta previa was also associated with higher likelihood of antepartum admission (10.3% vs 0%; P<.01), preterm delivery (34.5% vs 12%; P<.01), lower neonatal birthweight (median, 2847 g [interquartile range, 2655-3310] vs 3263 g [interquartile range, 2855-3560]), and cesarean delivery (100% vs 20.4%; P<.001), but there were no differences in overall pregnancy or neonatal outcomes.

CONCLUSION

In nulliparous individuals diagnosed with placenta previa on midtrimester ultrasound, older maternal age, previous pregnancy of <20 weeks, and in vitro fertilization are associated with persistent placenta previa at delivery.

Low-Dose Aspirin during Pregnancy and Postpartum Bleeding

OBJECTIVE

This study aimed to investigate whether aspirin 81 mg daily for preeclampsia prevention is associated with increased risk of postpartum blood loss at the time of delivery.

STUDY DESIGN

This is a retrospective cohort study performed at a tertiary hospital from January 2018 to April 2021. Data were extracted from the electronic medical record. Patients prescribed low-dose aspirin (LDA) were compared with patients who were not. The primary outcome was a composite of postpartum blood loss, defined as: estimated blood loss (EBL) >1,000 mL, documentation of International Classification of Diseases-9/-10 codes for postpartum hemorrhage (PPH), or red blood cell (RBC) transfusion. Bivariate analysis, and unadjusted and adjusted logistic regression modeling were performed.

RESULTS

Among 16,980 deliveries, 1,922 (11.3%) were prescribed LDA. Patients prescribed LDA were more likely to be >35 years old, nulliparous, obese, taking other anticoagulants, or have diagnoses of diabetes, systemic lupus erythematosus, fibroids, or hypertensive disease of pregnancy. After adjusting for potential confounders, the significant association between LDA use and the composite did not persist (adjusted odds ratio [aOR]: 1.1, 95% confidence interval [CI]: 1.0-1.3) nor did the association between EBL > 1,000 mL (aOR: 1.0, 95% CI: 0.9-1.3) and RBC transfusion (aOR: 1.3, 95% CI: 0.9-1.7). The association between LDA and PPH remained significant (aOR: 1.3, 95% CI: 1.1-1.6). Patients who discontinued LDA <7 days prior to delivery had an increased risk of the postpartum blood loss composite compared discontinuation ≥7 days (15.0 vs. 9.3%; p = 0.03).

CONCLUSION

There may be an association between LDA use and increased risk of postpartum bleeding. This suggests that use of LDA outside the recommended guidelines should be cautioned and further investigation is needed to determine its ideal dosing and timing of discontinuation.

KEY POINTS

· There may be an association with LDA and an increased risk of postpartum bleeding.. · Patients who discontinued LDA less than 7 days prior to delivery had an increased rate of postpartum bleeding.. · Additional research is need to determine optimal LDA dose and timing of discontinuation..

Macroscopic lesions of maternal and fetal vascular malperfusion in stillborn placentas: Diagnosis in the absence of microscopic histopathological examination

INTRODUCTION

Lesions of maternal vascular malperfusion (MVM) and fetal vascular malperfusion (FVM) are common in placentas associated with both stillbirth and live birth. The objective of this study was to identify lesions present more commonly in stillborn placentas and those most indicative of MVM and FVM without microscopic pathologic evaluation.

METHODS

Data were derived from the Stillbirth Collaborative Research Network. Lesions were identified according to standard protocols published previously and categorized as either MVM or FVM according to the Amsterdam Placental Workshop Group Consensus Statement and macroscopic "umbilical cord at risk" findings. Multivariate logistic regression was used to determine the odds of stillbirth with macroscopic findings of MVM or FVM.

RESULTS

595 stillbirths and 1,305 live births were analyzed. FVM lesions (85.2%) were marginally more common (though not statistically different) in stillbirths compared to MVM lesions (81.3%). Macroscopic findings of both MVM and FVM were more common in stillbirths versus livebirths (p < 0.001). Odds ratios of macroscopic MVM and FVM lesions for stillbirth, adjusted for gestational age at delivery, maternal race (minority), ethnicity (Hispanic), age, and history of hypertension or diabetes, were 1.48 (95% CI 1.30-1.69) and 1.34 (95% CI 1.18-1.53), respectively.

DISCUSSION

Macroscopic features of MVM and FVM are associated with higher odds of stillbirth versus live birth even when controlled for gestational age and maternal factors, which may be a useful clue in determining the pathophysiology of these events. This information is also useful for pathologists when microscopic examination is not available.

Breastfeeding initiation and duration among people with mild chronic hypertension: a secondary analysis of the Chronic Hypertension and Pregnancy trial

BACKGROUND

Increased duration of breastfeeding improves maternal cardiovascular health and may be especially beneficial in high-risk populations, such as those with chronic hypertension. Others have shown that individuals with hypertension are less likely to breastfeed, and there has been limited research aimed at supporting breastfeeding goals in this population. The impact of perinatal blood pressure control on breastfeeding outcomes among people with chronic hypertension is unknown.

OBJECTIVE

This study aimed to evaluate whether breastfeeding initiation and short-term duration assessed at the postpartum clinic visit differed according to perinatal blood pressure treatment strategy (targeting blood pressure <140/90 mm Hg vs reserving antihypertensive treatment for blood pressure ≥160/105 mm Hg).

STUDY DESIGN

We performed a secondary analysis of the Chronic Hypertension and Pregnancy trial. This was an open-label, multicenter, randomized trial where pregnant participants with mild chronic hypertension were randomized to receive antihypertensive medications with goal blood pressure <140/90 mm Hg (active treatment) or deferred treatment until blood pressure ≥160/105 mm Hg (control). The primary outcome was initiation and duration of breastfeeding, assessed at the postpartum clinic visit. We performed bivariate analyses and log-binomial and cumulative logit regression models, adjusting models for variables that were unbalanced in bivariate analyses. We performed additional analyses to explore the relationship between breastfeeding duration and blood pressure measurements at the postpartum visit.

RESULTS

Of the 2408 participants from the Chronic Hypertension and Pregnancy trial, 1444 (60%) attended the postpartum study visit and provided breastfeeding information. Participants in the active treatment group had different body mass index class distribution and earlier gestational age at enrollment, and (by design) were more often discharged on antihypertensives. Breastfeeding outcomes did not differ significantly by treatment group. In the active and control treatment groups, 563 (77.5%) and 561 (78.1%) initiated breastfeeding, and mean durations of breastfeeding were 6.5±2.3 and 6.3±2.1 weeks, respectively. The probability of ever breastfeeding (adjusted relative risk, 0.99; 95% confidence interval, 0.93-1.05), current breastfeeding at postpartum visit (adjusted relative risk, 1.01; 95% confidence interval, 0.94-1.10), and weeks of breastfeeding (adjusted odds ratio, 0.87; 95% confidence interval, 0.68-1.12) did not differ by treatment group. Increased duration (≥2 vs <2 weeks) of breastfeeding was associated with slightly lower blood pressure measurements at the postpartum visit, but these differences were not significant in adjusted models.

CONCLUSION

In a secondary analysis of the cohort of Chronic Hypertension and Pregnancy trial participants who attended the postpartum study visit and provided breastfeeding information (60% of original trial participants), breastfeeding outcomes did not differ significantly by treatment group. This suggests that maintaining goal blood pressure <140/90 mm Hg throughout the perinatal period is associated with neither harm nor benefit for short-term breastfeeding goals. Further study is needed to understand long-term breastfeeding outcomes among individuals with chronic hypertension and how to support this population in achieving their breastfeeding goals.

Association of maternal body mass index with success and outcomes of attempted operative vaginal delivery

BACKGROUND

Increasing maternal body mass index is associated with increased morbidity at cesarean delivery in a dose-dependent manner. In some clinical scenarios, operative vaginal delivery is a strategy to prevent the morbidity associated with second-stage cesarean delivery, but the relationship between maternal body mass index and outcomes of attempted operative vaginal delivery is not well characterized.

OBJECTIVE

This study aimed to assess whether the success of and adverse outcomes after attempted operative vaginal delivery are associated with maternal body mass index at delivery among nulliparous individuals.

STUDY DESIGN

This was a secondary analysis from the prospective cohort Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-To-Be study. This analysis included cephalic live-born nonanomalous singleton pregnancies ≥34 weeks at delivery with an attempted operative vaginal delivery (either forceps or vacuum). The primary exposure was maternal body mass index at delivery (≥30 vs <30 kg/m2 [referent]). The primary outcome was an unsuccessful operative vaginal delivery attempt, defined as a cesarean delivery after an attempted operative vaginal delivery. The secondary outcomes included maternal and neonatal adverse outcomes. Multivariable logistic regression was used, and statistical interaction between operative instrument type (vacuum vs forceps) and body mass index was assessed.

RESULTS

Of 10,038 assessed individuals, 791 (7.9%) had an attempted operative vaginal delivery and were included in this analysis. Of note, 325 individuals (41%) had a body mass index ≥30 kg/m2 at delivery. Overall, 42 of 791 participants (5%) experienced an unsuccessful operative vaginal delivery. Individuals with a body mass index ≥30 kg/m2 at delivery were more than twice as likely to have an unsuccessful operative vaginal delivery than those with a body mass index <30 kg/m2 (8.0% vs 3.4%; adjusted odds ratio, 2.23; 95% confidence interval, 1.16-4.28; P=.005). Composite maternal morbidity and composite neonatal morbidity did not vary by body mass index group. There was no evidence of interaction or effect modification by operative instrument type for the rate of unsuccessful operative vaginal delivery attempt, composite maternal morbidity, or composite neonatal morbidity.

CONCLUSION

Among nulliparous individuals who underwent an attempted operative vaginal delivery, those with a body mass index ≥30 kg/m2 at delivery were more likely to have an unsuccessful operative vaginal delivery attempt than those with a body mass index <30 kg/m2. There was no difference in composite maternal or neonatal morbidity after attempted operative vaginal delivery by body mass index category.

Risk Factors for Perinatal Transmission of Hepatitis C Virus

OBJECTIVE

To estimate the rate of perinatal transmission of hepatitis C virus (HCV) infection, to identify risk factors for perinatal transmission of HCV infection, and to determine the viremic threshold for perinatal transmission.

METHODS

This was a prospective, multicenter, observational study of pregnant individuals at less than 24 weeks of gestation screened for HCV infection from 2012 to 2018 in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. Individuals found to be HCV antibody-positive were followed throughout pregnancy. Children were followed for evidence of perinatal transmission at 2-6 months (HCV RNA testing) and at 18-24 months (HCV RNA and antibody testing) of life. The primary outcome was perinatal transmission, defined as positive test results at either follow-up time point.

RESULTS

A total of 109,379 individuals were screened for HCV infection. Of the 1,224 participants who screened positive, 772 (63.1%) enrolled and 432 of those 772 (56.0%) had data available to assess primary outcome. The overall rate of perinatal transmission was 6.0% (26/432, 95% CI 4.0-8.7%). All children with HCV infection were born to individuals with demonstrable viremia. In viremic participants (n=314), the perinatal transmission rate was 8.0% (95% CI 5.2-11.5%). Risk factors for perinatal transmission included HCV RNA greater than 106 international units/mL (adjusted odds ratio [aOR] 8.22, 95% CI 3.16-21.4) and vaginal bleeding reported at any time before delivery (aOR 3.26, 95% CI 1.32-8.03). A viremic threshold for perinatal transmission could not be established.

CONCLUSION

Perinatal transmission of HCV infection was limited to viremic individuals. High viral loads and antepartum bleeding were associated with perinatal transmission.

Outcomes of induction vs prelabor cesarean delivery at <33 weeks for hypertensive disorders of pregnancy

BACKGROUND

Hypertensive disorders of pregnancy are the leading cause of indicated preterm birth; however, the optimal delivery approach for pregnancies complicated by preterm hypertensive disorders of pregnancy remains uncertain.

OBJECTIVE

This study aimed to compare maternal and neonatal morbidity in patients with hypertensive disorders of pregnancy who either went induction of labor or prelabor cesarean delivery at <33 weeks' gestation. In addition, we aimed to quantify the length of induction of labor and rate of vaginal delivery in those who underwent induction of labor.

STUDY DESIGN

This is a secondary analysis of an observational study which included 115,502 patients in 25 hospitals in the United States from 2008 to 2011. Patients were included in the secondary analysis if they were delivered for pregnancy associated hypertension (gestational hypertension or preeclampsia) between 230 and <330 weeks' gestation; and were excluded for known fetal anomalies, multiple gestation, fetal malpresentation or demise, or a contraindication to labor. Maternal and neonatal adverse composite outcomes were evaluated by intended mode of delivery. Secondary outcomes were duration of labor induction and rate of cesarean delivery in those who underwent labor induction.

RESULTS

A total of 471 patients met inclusion criteria, of whom 271 (58%) underwent induction of labor and 200 (42%) underwent prelabor cesarean delivery. Composite maternal morbidity was 10.2% in the induction group and 21.1% in the cesarean delivery group (unadjusted odds ratio, 0.42 [0.25-0.72]; adjusted odds ratio, 0.44 [0.26-0.76]). Neonatal morbidity in the induction group vs the cesarean delivery was 51.9% and 63.8 %, respectively (unadjusted odds ratio, 0.61 [0.42-0.89]; adjusted odds ratio, 0.71 [0.48-1.06]). The frequency of vaginal delivery in the induction group was 53% (95% confidence interval, 46.8-58.7) and the median duration of labor was 13.9 hours (interquartile range, 8.7-22.2). The frequency of vaginal birth was higher in patients at or beyond 29 weeks (39.9% at 240-286 weeks, 56.3% at 290-<330 weeks; P=.01).

CONCLUSION

Among patients delivered for hypertensive disorders of pregnancy <330 weeks, labor induction compared with prelabor cesarean delivery is associated with significantly lower odds of maternal but not neonatal morbidity. More than half of patients induced delivered vaginally, with a median duration of labor induction of 13.9 hours.

Association of Living in a Food Desert and Poor Periconceptional Diet Quality in a Cohort of Nulliparous Pregnant Individuals

BACKGROUND

A poor diet can result from adverse social determinants of health and increases the risk of adverse pregnancy outcomes.

OBJECTIVE

We aimed to assess, using data from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be prospective cohort, whether nulliparous pregnant individuals who lived in a food desert were more likely to experience poorer periconceptional diet quality compared with those who did not live in a food desert.

METHODS

The exposure was living in a food desert based on a spatial overview of food access indicators by income and supermarket access per the Food Access Research Atlas. The outcome was periconceptional diet quality per the Healthy Eating Index (HEI)-2010, analyzed by quartile (Q) from the highest or best (Q4, reference) to the lowest or worst dietary quality (Q1); and secondarily, nonadherence (yes or no) to 12 key aspects of dietary quality.

RESULTS

Among 7,956 assessed individuals, 24.9% lived in a food desert. The mean HEI-2010 score was 61.1 of 100 (SD: 12.5). Poorer periconceptional dietary quality was more common among those who lived in a food desert compared with those who did not live in a food desert (Q4: 19.8%, Q3: 23.6%, Q2: 26.5%, and Q1: 30.0% vs. Q4: 26.8%, Q3: 25.8%, Q2: 24.5%, and Q1: 22.9%; overall P < 0.001). Individuals living in a food desert were more likely to report a diet in lower quartiles of the HEI-2010 (i.e., poorer dietary quality) (aOR: 1.34 per quartile; 95% CI: 1.21, 1.49). They were more likely to be nonadherent to recommended standards for 5 adequacy components of the HEI-2010, including fruit, total vegetables, greens and beans, seafood and plant proteins, and fatty acids, and less likely to report excess intake of empty calories.

CONCLUSIONS

Nulliparous pregnant individuals living in a food desert were more likely to experience poorer periconceptional diet quality compared with those who did not live in a food desert.

PROMPT: Prospective Meta-analysis for Pessary Trials Study Protocol

OBJECTIVE

 Preterm birth, defined as birth before 37 weeks of gestation, is a leading cause of perinatal and infant mortality throughout the world. Preterm birth is also associated with long-term neurological disabilities and other significant health issues in children. A short cervix in the second trimester has been noted to be one of the strongest predictors of subsequent spontaneous preterm birth in both singleton and multiple pregnancies. Some studies have shown that cervical support in the form of an Arabin pessary lowers the risk of preterm birth in women with a singleton gestation and short cervical length; however, other studies have conflicting results. Our objective was to form an international collaborative of planned or ongoing randomized trials of pessary in singleton and twin gestations with a short cervix.

STUDY DESIGN

 In November 2014, an international group of investigators, who had initiated or were planning randomized trials of pessary for pregnant people with a short cervix and singleton or twin gestation to prevent preterm birth, formed a collaboration to plan a prospective individual patient data (IPD) meta-analysis of randomized trials (PROspective Meta-analysis of Pessary Trials [PROMPT]). The PROMPT investigators agreed on meta-analysis IPD hypotheses for singletons and twins, eligibility criteria, and a set of core baseline and outcome measures. The primary outcome is a composite of fetal death or preterm delivery before 32 weeks' gestation. Secondary outcomes include maternal and neonatal morbidities. The PROMPT protocol may be viewed as a written agreement among the study investigators who make up the PROMPT consortium (PROSPERO ID# CRD42018067740).

RESULTS

 Results will be published in phases as the individual participating studies are concluded and published. Results of the first phase of singleton and twin pessary trials are expected to be available in late 2022. Updates are planned as participating trials are completed and published.

KEY POINTS

· Short cervical length predicts preterm birth.. · Results of prior cervical pessary trials are mixed.. · Meta-analysis of pessary trials protocol..

Maternal and Delivery Characteristics and Self-Reported Perceived Control During Labor

OBJECTIVE

To evaluate the association between maternal and delivery characteristics and self-reported perceived control during childbirth.

METHODS

A secondary analysis of a multicenter randomized trial was conducted to compare labor induction at 39 weeks of gestation with expectant management in low-risk nulliparous people. Six to 96 hours after delivery, participants who experienced labor completed the Labor Agentry Scale, a validated self-administered questionnaire to ascertain perceived control during childbirth. Scores range from 29 to 203, with higher scores indicating a sense of greater control. Multivariable linear regression was used to determine which maternal and delivery characteristics were associated with the Labor Agentry Scale score. Eligible characteristics included age, self-reported race and ethnicity, marital status, employment status, type of insurance, previous pregnancy loss before 20 weeks of gestation, body mass index (BMI), smoking, alcohol use, mode of delivery, labor pain (0-10 points), and a composite of perinatal death or severe neonatal complications. Significant variables ( P <.05) were retained in the final multivariable model, and adjusted mean differences (95% CIs) between groups were estimated.

RESULTS

Of 6,106 people enrolled in the trial, 6,038 experienced labor, of whom 5,750 (95.2%) completed the Labor Agentry Scale and were included in this analysis. Mean [95% CI] adjusted Labor Agentry Scale scores were significantly lower among those who identified as Asian (-6.4 [-10.5 to -2.3]) or Hispanic (-3.7 [-5.7 to -1.7]) compared with White, smoked compared with did not smoke (-2.8 [-5.5 to -0.1]), had BMIs of 35 or higher compared with less than 30 (-2.0 [-3.8 to -0.2]), were unemployed (-3.15 [-4.76 to -1.55]), did not have private health insurance (-2.61 [-4.47 to -0.76]), underwent operative vaginal (-5.1 [-7.7 to -2.6]) or cesarean (-14.4 [-16.1 to -12.6]) delivery compared with spontaneous vaginal delivery, and reported greater labor pain score of 8 or higher compared with less than 8 (-11.9 [-13.4 to -10.4]). Mean [95% CI] adjusted Labor Agentry Scale scores were significantly higher among people who were employed compared with unemployed (3.2 [1.6-4.8]) and had private compared with nonprivate insurance (2.6 [0.76-4.5]).

CONCLUSION

In nulliparous people at low risk, unemployment, lack of private health insurance, Asian race, Hispanic ethnicity, smoking, operative delivery, and more labor pain were associated with lower perceived control during labor.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov , NCT01990612.

Hypertensive Disorders of Pregnancy and Long-Term Maternal Cardiovascular and Metabolic Biomarkers

OBJECTIVE

 This study aimed to measure the association between hypertensive disorders of pregnancy (HDP) and long-term maternal metabolic and cardiovascular biomarkers.

STUDY DESIGN

 Follow-up study of patients who completed glucose tolerance testing 5 to 10 years after enrollment in a mild gestational diabetes mellitus (GDM) treatment trial or concurrent non-GDM cohort. Maternal serum insulin concentrations and cardiovascular markers VCAM-1, VEGF, CD40L, GDF-15, and ST-2 were measured, and insulinogenic index (IGI, pancreatic β-cell function) and 1/ homeostatic model assessment (insulin resistance) were calculated. Biomarkers were compared by presence of HDP (gestational hypertension or preeclampsia) during pregnancy. Multivariable linear regression estimated the association of HDP with biomarkers, adjusting for GDM, baseline body mass index (BMI), and years since pregnancy.

RESULTS

 Of 642 patients, 66 (10%) had HDP: 42 with gestational hypertension and 24 with preeclampsia. Patients with HDP had higher baseline and follow-up BMI, higher baseline blood pressure, and more chronic hypertension at follow-up. HDP was not associated with metabolic or cardiovascular biomarkers at follow-up. However, when HDP type was evaluated, patients with preeclampsia had lower GDF-15 levels (oxidative stress/cardiac ischemia), compared with patients without HDP (adjusted mean difference: -0.24, 95% confidence interval: -0.44, -0.03). There were no differences between gestational hypertension and no HDP.

CONCLUSION

 In this cohort, metabolic and cardiovascular biomarkers 5 to 10 years after pregnancies did not differ by HDP. Patients with preeclampsia may have less oxidative stress/cardiac ischemia postpartum; however, this may have been observed due to chance alone given multiple comparisons. Longitudinal studies are needed to define the impact of HDP during pregnancy and interventions postpartum.

KEY POINTS

· Hypertensive disorders of pregnancy were not associated with metabolic dysfunction.. · Cardiovascular dysfunction was not consistently seen after pregnancy hypertension.. · Longitudinal studies with postpartum interventions after preeclampsia are needed..

Association between sleep disordered breathing and neonatal outcomes in nulliparous individuals

BACKGROUND

To determine whether objectively measured Sleep-Disordered Breathing (SDB) during pregnancy is associated with an increased risk of adverse neonatal outcomes in a cohort of nulliparous individuals.

METHODS

Secondary analysis of the nuMom2b- sleep disordered breathing substudy was performed. Individuals underwent in-home sleep studies for SDB assessment in early- (6-15 weeks' gestation) and mid-pregnancy (22-31 weeks' gestation). SDB was defined as an apnea-hypopnea index ≥5 events/hour at either time point. Primary outcome was a composite outcome of respiratory distress syndrome, transient tachypnea of the newborn, or receipt of respiratory support, treated hyperbilirubinemia or hypoglycemia, large-for-gestational age (LGA), seizures treated with medications or confirmed by electroencephalography, confirmed sepsis, or neonatal death. Individuals were categorized into 1) early pregnancy SDB (6-15 weeks' gestation), 2) new onset mid-pregnancy SDB (22-31 weeks' gestation), and 3) no SDB. Log-binomial regression was used to calculate adjusted risk ratios (RR) and 95% confidence intervals (CI) representing the association. Adjustments were made for maternal age, chronic hypertension, pregestational diabetes, progesterone use and Body Mass Index (BMI), new onset mid-pregnancy SDB to establish if a relationship was still present.

RESULTS

Among 2,106 participants, 3% percent (n=75) had early pregnancy SDB and 5.7% (n=119) developed new onset mid-pregnancy SDB. The incidence of the primary outcome was higher in offspring of individuals with early- (29.3%) and new onset mid- pregnancy SDB (30.3%) compared to individuals with no SDB (17.8%). After adjustment for maternal age, chronic hypertension, pregestational diabetes, progesterone use and BMI, new onset mid-pregnancy SDB conferred increased risk (RR=1.42, 95% CI: 1.05, 1.92), where there was no longer statistically significant association between early pregnancy SDB and the primary outcome.

CONCLUSION

New Onset, Mid- pregnancy SDB is independently associated with neonatal morbidity.

Researching COVID to Enhance Recovery (RECOVER) adult study protocol: Rationale, objectives, and design

IMPORTANCE

SARS-CoV-2 infection can result in ongoing, relapsing, or new symptoms or other health effects after the acute phase of infection; termed post-acute sequelae of SARS-CoV-2 infection (PASC), or long COVID. The characteristics, prevalence, trajectory and mechanisms of PASC are ill-defined. The objectives of the Researching COVID to Enhance Recovery (RECOVER) Multi-site Observational Study of PASC in Adults (RECOVER-Adult) are to: (1) characterize PASC prevalence; (2) characterize the symptoms, organ dysfunction, natural history, and distinct phenotypes of PASC; (3) identify demographic, social and clinical risk factors for PASC onset and recovery; and (4) define the biological mechanisms underlying PASC pathogenesis.

METHODS

RECOVER-Adult is a combined prospective/retrospective cohort currently planned to enroll 14,880 adults aged ≥18 years. Eligible participants either must meet WHO criteria for suspected, probable, or confirmed infection; or must have evidence of no prior infection. Recruitment occurs at 86 sites in 33 U.S. states, Washington, DC and Puerto Rico, via facility- and community-based outreach. Participants complete quarterly questionnaires about symptoms, social determinants, vaccination status, and interim SARS-CoV-2 infections. In addition, participants contribute biospecimens and undergo physical and laboratory examinations at approximately 0, 90 and 180 days from infection or negative test date, and yearly thereafter. Some participants undergo additional testing based on specific criteria or random sampling. Patient representatives provide input on all study processes. The primary study outcome is onset of PASC, measured by signs and symptoms. A paradigm for identifying PASC cases will be defined and updated using supervised and unsupervised learning approaches with cross-validation. Logistic regression and proportional hazards regression will be conducted to investigate associations between risk factors, onset, and resolution of PASC symptoms.

DISCUSSION

RECOVER-Adult is the first national, prospective, longitudinal cohort of PASC among US adults. Results of this study are intended to inform public health, spur clinical trials, and expand treatment options.

REGISTRATION

NCT05172024.

Searching and visualizing genetic associations of pregnancy traits by using GnuMoM2b

Adverse pregnancy outcomes (APOs) are major risk factors for women's health during pregnancy and even in the years after pregnancy. Due to the heterogeneity of APOs, only few genetic associations have been identified. In this report, we conducted genome-wide association studies (GWAS) of 479 traits that are possibly related to APOs using a large and racially diverse study, Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b). To display the extensive results, we developed a web-based tool GnuMoM2b ( https://gnumom2b.cumcobgyn.org/ ) for searching, visualizing, and sharing results from GWAS of 479 pregnancy traits as well as phenome-wide association studies (PheWAS) of more than 17 million single nucleotide polymorphisms (SNPs). The genetic results from three ancestries (Europeans, Africans, and Admixed Americans) and meta-analyses are populated in GnuMoM2b. In conclusion, GnuMoM2b is a valuable resource for extraction of pregnancy-related genetic results and shows the potential to facilitate meaningful discoveries.

Genetic Associations with Dynamic Placental Proteins Identify Causal Biomarkers for Hypertension in Pregnancy

Preeclampsia (PE), a gestational hypertensive disorder, ranks as the second leading cause of maternal mortality worldwide. While PE is considered a multifactorial disease, placental insufficiency is believed to drive its progression. To noninvasively study placental physiology related to adverse pregnancy outcomes (APOs) and predict these outcomes before symptom onset, we measured nine placental protein levels in first- and second-trimester serum samples from 2,352 nulliparous pregnant women in the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers- to-Be (nuMoM2b) study. The proteins analyzed include VEGF, PlGF, ENG, sFlt-1, ADAM-12, PAPP-A, fβHCG, INHA, and AFP. Currently, little is known about the genetic variants contributing to the heritability of these proteins during pregnancy, and no studies have explored the causal relationships between early pregnancy proteins and gestational hypertensive disorders. Our study has three objectives. First, we conducted genome-wide association study (GWAS) of nine placental proteins in maternal serum during the first and second trimesters and the difference between time points to understand how genetics may influence placental proteins in early pregnancy. Second, we examined whether early pregnancy placental proteins are causal factors for PE and gestational hypertension (gHTN). Lastly, we investigated the causal relationship between PE/gHTN and long-term HTN. In conclusion, our study discovered significant genetic associations with placental proteins ADAM-12, VEGF, and sFlt-1, offering insights into their regulation during pregnancy. Mendelian randomization (MR) analyses demonstrated evidence of causal relationships between placental proteins, particularly ADAM-12, and gHTN, potentially informing prevention and treatment strategies. Our findings suggest that placental proteins like ADAM-12 could serve as biomarkers for postpartum HTN risk.

Copy number variants and fetal growth in stillbirths

BACKGROUND

Fetal growth abnormalities are associated with a higher incidence of stillbirth, with small and large for gestational age infants incurring a 3 to 4- and 2 to 3-fold increased risk, respectively. Although clinical risk factors such as diabetes, hypertension, and placental insufficiency have been associated with fetal growth aberrations and stillbirth, the role of underlying genetic etiologies remains uncertain.

OBJECTIVE

This study aimed to assess the relationship between abnormal copy number variants and fetal growth abnormalities in stillbirths using chromosomal microarray.

STUDY DESIGN

A secondary analysis utilizing a cohort study design of stillbirths from the Stillbirth Collaborative Research Network was performed. Exposure was defined as abnormal copy number variants including aneuploidies, pathogenic copy number variants, and variants of unknown clinical significance. The outcomes were small for gestational age and large for gestational age stillbirths, defined as a birthweight <10th percentile and greater than the 90th percentile for gestational age, respectively.

RESULTS

Among 393 stillbirths with chromosomal microarray and birthweight data, 16% had abnormal copy number variants. The small for gestational age outcome was more common among those with abnormal copy number variants than those with a normal microarray (29.5% vs 16.5%; P=.038). This finding was consistent after adjusting for clinically important variables. In the final model, only abnormal copy number variants and maternal age remained significantly associated with small for gestational age stillbirths, with an adjusted odds ratio of 2.22 (95% confidence interval, 1.12-4.18). Although large for gestational age stillbirths were more likely to have an abnormal microarray: 6.2% vs 3.3% (P=.275), with an odds ratio of 2.35 (95% confidence interval, 0.70-7.90), this finding did not reach statistical significance.

CONCLUSION

Genetic abnormalities are more common in the setting of small for gestational age stillborn fetuses. Abnormal copy number variants not detectable by traditional karyotype make up approximately 50% of the genetic abnormalities in this population.