Fetal Growth Biometry as Predictors of Shoulder Dystocia in a Low-Risk Obstetrical Population

OBJECTIVE

 This study aimed to evaluate fetal biometrics as predictors of shoulder dystocia (SD) in a low-risk obstetrical population.

STUDY DESIGN

 Participants were enrolled as part of a U.S.-based prospective cohort study of fetal growth in low-risk singleton gestations (n = 2,802). Eligible women had liveborn singletons ≥2,500 g delivered vaginally. Sociodemographic, anthropometric, and pregnancy outcome data were abstracted by research staff. The diagnosis of SD was based on the recorded clinical impression of the delivering physician. Simple logistic regression models were used to examine associations between fetal biometrics and SD. Fetal biometric cut points, selected by Youden's J and clinical determination, were identified to optimize predictive capability. A final model for SD prediction was constructed using backward selection. Our dataset was randomly divided into training (60%) and test (40%) datasets for model building and internal validation.

RESULTS

 A total of 1,691 women (98.7%) had an uncomplicated vaginal delivery, while 23 (1.3%) experienced SD. There were no differences in sociodemographic or maternal anthropometrics between groups. Epidural anesthesia use was significantly more common (100 vs. 82.4%; p = 0.03) among women who experienced SD compared with those who did not. Amniotic fluid maximal vertical pocket was also significantly greater among SD cases (5.8 ± 1.7 vs. 5.1 ± 1.5 cm; odds ratio = 1.32 [95% confidence interval: 1.03,1.69]). Several fetal biometric measures were significantly associated with SD when dichotomized based on clinically selected cut-off points. A final prediction model was internally valid with an area under the curve of 0.90 (95% confidence interval: 0.81, 0.99). At a model probability of 1%, sensitivity (71.4%), specificity (77.5%), positive (3.5%), and negative predictive values (99.6%) did not indicate the ability of the model to predict SD in a clinically meaningful way.

CONCLUSION

 Other than epidural anesthesia use, neither sociodemographic nor maternal anthropometrics were significantly associated with SD in this low-risk population. Both individually and in combination, fetal biometrics had limited ability to predict SD and lack clinical usefulness.

KEY POINTS

· SD unpredictable in low-risk women.. · Fetal biometry does not reliably predict SD.. · Epidural use associated with increased SD risk.. · SD prediction models clinically inefficient..

Racial, Ethnic, and Geographic Differences in Vaginal Birth After Cesarean Delivery in the US, 2011-2021

This cross-sectional study examines racial, ethnic, and geographic differences in vaginal birth after cesarean delivery in the US, from 2011 to 2021.

Association between Sleep Disordered Breathing and Neonatal Outcomes in Nulliparous Individuals

OBJECTIVE

 Our objective was 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.

STUDY DESIGN

 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/h at either time point. The 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, 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 (CIs) representing the association.

RESULTS

 Among 2,106 participants, 3% (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 the offspring of individuals with early (29.3%) and new onset mid-pregnancy SDB (30.3%) compared with individuals with no SDB (17.8%). After adjustment for maternal age, chronic hypertension, pregestational diabetes, and body mass index, new onset mid-pregnancy SDB conferred increased risk (RR = 1.43, 95% CI: 1.05, 1.94), 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.

KEY POINTS

· SDB is a common condition impacting pregnancy with known maternal risks.. · Objectively defined SDB in pregnancy was associated with a composite of adverse neonatal outcomes.. · New onset SDB in mid pregnancy conferred statistically significant increased risk..

Association of Prostaglandin Use for Cervical Ripening with Mode of Delivery in Small for Gestational Age versus Non-Small for Gestational Age Neonates

OBJECTIVE

 Prostaglandins (PGs) use for cervical ripening with small for gestational age (SGA) fetuses is controversial since it remains uncertain if use increases the chance of cesarean delivery (CD). We aimed to assess the association between PG use for cervical ripening and mode of delivery between SGA and appropriate for gestational age (AGA) neonates.

STUDY DESIGN

 Secondary analysis of the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b), a prospective observational cohort study of 10,038 nulliparas. We included women undergoing induction with nonanomalous fetuses in the cephalic presentation. Women with >2 cm cervical dilation or prior uterine scar were excluded. We assessed the association of PG use with CD among women with SGA and AGA neonates. SGA was defined as birth weight <10th percentile for gestational age and sex. Multivariable logistic regression was used to adjust for potential confounders and test for interaction. Secondary outcomes included adverse neonatal outcomes, indication for CD, maternal hemorrhage, and chorioamnionitis.

RESULTS

 Among 2,353 women eligible, PGs were used in 54.8%, SGA occurred in 15.1%, and 35.0% had CD. The association between PG use and CD differed significantly (interaction p = 0.018) for SGA versus AGA neonates; CD occurred more often in SGA neonates exposed to PGs than not (35 vs. 22%, p = 0.009). PG use was not associated with CD among AGA neonates (36 vs. 36%, p = 0.8). This effect remained significant when adjusting for body mass index, race/ethnicity, and cervical dilation. Among SGA neonates, CD for "nonreassuring fetal status" was similar between PG groups. Among SGA neonates, PG use was not associated with adverse neonatal outcomes or postpartum hemorrhage but had a higher rate of chorioamnionitis (7.0 vs. 2.1%, p = 0.048).

CONCLUSION

 PG use was associated with a higher rate of CD in SGA but not AGA neonates; however, further studies are needed before PG use is discouraged with SGA neonates.

KEY POINTS

· PGs are commonly used for cervical ripening.. · PG use was associated with increased risk of cesarean delivery in SGA neonates.. · PG use was not associated with adverse neonatal outcomes..

Adverse Pregnancy Outcomes and Pharyngeal Flow Limitation during Sleep: Nulliparous Pregnancy Outcomes Study Monitoring Mothers-to-be (nuMoM2b)

RATIONALE

Pharyngeal flow limitation during pregnancy may be a risk factor for adverse pregnancy outcomes but was previously challenging to quantify.

OBJECTIVE

To determine whether a novel objective measure of flow limitation identifies an increased risk of preeclampsia (primary outcome) and other adverse outcomes in a prospective cohort: Nulliparous Pregnancy Outcomes Study Monitoring Mothers-to-be.

METHODS

Flow limitation severity scores (0%=fully obstructed, 100%=open airway)- quantified from breath-by-breath airflow shape-were obtained from home sleep tests during early (6-15 weeks) and mid (22-31 weeks) pregnancy. Multivariable logistic regression quantified associations between flow limitation (median overnight severity, both time-points averaged) and preeclampsia, adjusting for maternal age, body mass index (BMI), race, ethnicity, chronic hypertension, and flow limitation during wakefulness. Secondary outcomes were hypertensive disorders of pregnancy (HDP), gestational diabetes mellitus (GDM), and infant birthweight.

RESULTS

Of 1939 participants with flow limitation data at both time-points (age: 27.0±5.4 yr [mean±sd], BMI: 27.7±6.1 kg·m-2), 5.8% developed preeclampsia, 12.7% developed HDP, and 4.5% developed GDM. Greater flow limitation was associated with increased preeclampsia risk: adjusted Odds Ratio (OR) 2.49, 95% Confidence Interval [1.69, 3.69], per 2SD increase in severity. Findings persisted in women without sleep apnea (apnea-hypopnea index <5 events·hr-1). Flow limitation was associated with HDP (OR: 1.77 [1.33, 2.38]) and reduced infant birthweight (83.7 [31.8, 135.6] g), but not GDM.

CONCLUSIONS

Greater flow limitation is associated with increased risk of preeclampsia, HDP, and lower infant birthweight. Flow limitation may provide an early target for mitigating the consequences of sleep disordered breathing during pregnancy.

The Diagnostic Utility of Growth Ultrasound for the Indication of Maternal Overweight or Obesity

OBJECTIVE

 The objective of this study was to evaluate the diagnostic utility of serial growth ultrasounds for the indication of maternal overweight or obesity.

STUDY DESIGN

 This is a retrospective cohort study of all women with a body mass index ≥25 kg/m2 who underwent at least one growth ultrasound at ≥24 weeks gestation and delivered at a single tertiary care institution between January 2010 and December 2013. Women were excluded if they had other medical indications for growth ultrasounds. Ultrasounds were divided into three gestational age epochs: 24 to 316/7 weeks, 32 to 356/7 weeks, and ≥36 weeks. Outcomes examined included the accuracy of sonographic detection of fetal growth restriction (FGR) and fetal overgrowth compared with diagnoses of small for gestational age (SGA) and large for gestational age (LGA) based on the birth weight. The test characteristics of ultrasound and the number needed to screen (NNS) to detect growth abnormalities at the time of birth were estimated for each condition and gestational age epoch. The NNS for the detection of fluid abnormalities was also assessed.

RESULTS

 During the study period, 3,945 eligible sonograms were performed in 2,928 women. FGR was identified on ultrasound in 42 (1.4%) women, fetal overgrowth in 94 (3.2%) women, oligohydramnios in 35 (1.2%) women, and hydramnios in 41 (1.4%) women. The NNS for the diagnoses of SGA, LGA, oligohydramnios, and hydramnios at delivery was at least 137 prior to 32 weeks of gestation and decreased (i.e., at least 45 and 16, for 32 to 356/7 weeks and ≥36 weeks, respectively) with advancing gestational age epochs.

CONCLUSION

 If growth ultrasounds are to be performed for the sole indication of maternal overweight or obesity, consideration should be given to delaying initiation until at least 32 weeks of gestation given the infrequency of growth and fluid abnormalities identified earlier.

KEY POINTS

· There are limited data to support serial growth ultrasounds in overweight and obese women.. · The sensitivity of ultrasound for growth abnormalities at <32 weeks is low in women with BMI ≥25. · Consideration should be given to delaying initiation of growth ultrasounds until at least 32 weeks.

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.

Changes in Age Distribution and Maternal Mortality in a Subset of the US, 2014-2021

INTRODUCTION

This study aimed to determine the association between changes in age distribution and maternal mortality rates (MMR) in a subset of the United States between 2014 and 2021.

METHODS

A serial cross-sectional analysis of birthing individuals aged 15-44 years from 2014 to 2021 was performed. States that had not adopted the pregnancy checkbox as of 2014 were excluded from the primary analysis. A significant inflection point in MMR was identified in 2019 with the Joinpoint Regression Program, so all analyses were stratified: 2014-2019 and 2019-2021. The Kitagawa decomposition was applied to quantify the contribution from (1) changes in age distribution and (2) changes in age-specific MMR (ASMR) to total MMR. Data analysis occurred between 2022 and 2023.

RESULTS

From 2014 to 2021, the mean (standard deviation) age of birthing individuals changed from 28.3 (5.8) to 29.4 (5.7) years. The MMR (95% CI) increased significantly from 16.5 (15.8-18.5) to 18.9 (17.4-20.5) per 100,000 live births from 2014 to 2019 with acceleration in MMR to 31.8 (30.0-33.8) by 2021. The change in maternal age distribution contributed to 36% of the total change in the MMR from 2014 to 2019 and 4% from 2019 to 2021. Age-specific MMR components increased significantly for those aged 25-29 years and 30-34 years from 2014 to 2019. All 5-year age strata except the 15-19 year old group saw increases in age-specific MMR from 2019 to 2021.

CONCLUSIONS

MMR increased significantly from 2014 to 2021 with rapid increase after 2019. However, older age of birthing individuals explained only a minority of the increased MMR in both periods. The greatest contribution to MMR arose from increases in age-specific MMR.

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 .

The role of labor induction in modern obstetrics

A primary goal of obstetrical practice is the optimization of maternal and perinatal health. This goal translates into a seemingly simple assessment with regard to considerations of the timing of delivery: delivery should occur when the benefits are greater than those of continued pregnancy. In the absence of an indication for cesarean delivery, planned delivery is initiated with induction of labor. When medical or obstetrical complications exist, they may guide recommendations regarding the timing of delivery. In the absence of these complications, gestational age also has been used to guide delivery timing, given its association with both maternal and perinatal adverse outcomes. If there is no medical indication, delivery before 39 weeks has been discouraged, given its association with greater chances of adverse perinatal outcomes. Conversely, it has been recommended that delivery occur by 42 weeks of gestation, given the perinatal risks that accrue in the post-term period. Historically, a 39-week induction of labor, particularly for individuals with no previous birth, has not been routinely offered in the absence of medical or obstetrical indications. That approach was based on numerous observational studies that demonstrated an increased risk of cesarean delivery and other adverse outcomes among individuals who underwent labor induction compared to those in spontaneous labor. However, from a management and person-centered-choice perspective, the relevant comparison is between those undergoing planned labor induction at a given time vs those planning to continue pregnancy beyond that time. When individuals have been compared using that rubric-either in observational studies or randomized trials that have been performed in a wide variety of locations and populations- there has not been evidence that induction increases adverse perinatal or maternal outcomes. Conversely, even when the only indication for delivery is the achievement of a full-term gestational age, evidence suggests that multiple different outcomes, including cesarean delivery, hypertensive disorders of pregnancy, neonatal respiratory impairment, and perinatal mortality, are less likely when induction is performed. This information underscores the importance of making the preferences of pregnant individuals for different birth processes and outcomes central to the approach to delivery timing.

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.

NuMoM2b Study Insights: Primary Exposures, Outcomes, and Directions for Future Research

OBJECTIVE

 To summarize the publications to date from a large obstetric cohort of nulliparous individuals.

STUDY DESIGN

 We summarized all of the publications from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-be (nuMoM2b). We descriptively summarized the most common outcomes and exposures reported in current publications.

RESULTS

 Fifty-six publications to date are discussed. The most common primary exposures reported are participant baseline characteristics such as body mass index (24%), sociodemographic characteristics (22%), and sleep factors (16%). These exposures were most commonly measured in the first trimester (77%). The most commonly reported primary outcomes were related to adverse pregnancy outcomes (APOs, 51.6%), with 25% using a composite of multiple APOs as the primary outcome. At least 8,000 participants were used in the analyses of over half of the publications.

CONCLUSION

 The nuMoM2b study has generated a diverse array of publications and conclusions on factors associated with APOs. The publicly available data set from the nuMoM2b study continues to hold potential for considerable advances, new insights, and future research opportunities to optimize pregnancy and pregnancy-related health.

KEY POINTS

· The nuMoM2b pregnancy cohort has generated 56 publications thus far.. · The main findings of these publications are summarized and categorized in this work.. · The data and specimens from this cohort are available and can answer many clinical questions..

Postpartum pharmacologic thromboprophylaxis and complications in a US cohort

BACKGROUND

Venous thromboembolism accounts for approximately 9% of pregnancy-related deaths in the United States. National guidelines recommend postpartum risk stratification and pharmacologic prophylaxis in at-risk individuals. Knowledge on modern rates of postpartum pharmacologic thromboprophylaxis and its associated risks is limited.

OBJECTIVE

This study aimed to describe the rate of, and factors associated with, initiation of postpartum pharmacologic prophylaxis for venous thromboembolism, and to assess associated adverse outcomes.

STUDY DESIGN

This was a secondary analysis of a multicenter cohort of individuals delivering on randomly selected days at 17 US hospitals (2019-2020). Medical records were reviewed by trained and certified personnel. Those with an antepartum diagnosis of venous thromboembolism, receiving antepartum anticoagulation, or known SARS-CoV-2 infection were excluded. The primary outcome was use of postpartum pharmacologic thromboprophylaxis. Secondary outcomes included bleeding complications, surgical site infection, hospital readmission, and venous thromboembolism through 6 weeks postpartum. The rate of thromboprophylaxis administration was assessed by mode of delivery, institution, and continuance to the outpatient setting. Multivariable regression models were developed using k-fold cross-validation with stepwise backward elimination to evaluate factors associated with thromboprophylaxis administration. Univariable and multivariable logistic models with propensity score covariate adjustment were performed to assess the association between thromboprophylaxis administration and adverse outcomes.

RESULTS

Of 21,114 individuals in the analytical cohort, 11.9% (95% confidence interval, 11.4%-12.3%) received postpartum pharmacologic thromboprophylaxis; the frequency of receipt was 29.8% (95% confidence interval, 28.7%-30.9%) following cesarean and 3.5% (95% confidence interval, 3.2%-3.8%) following vaginal delivery. Institutional rates of prophylaxis varied from 0.21% to 34.8%. Most individuals (83.3%) received thromboprophylaxis only as inpatients. In adjusted analysis, cesarean delivery (adjusted odds ratio, 19.17; 95% confidence interval, 16.70-22.00), hysterectomy (adjusted odds ratio, 15.70; 95% confidence interval, 4.35-56.65), and obesity (adjusted odds ratio, 3.45; 95% confidence interval, 3.02-3.95) were the strongest factors associated with thromboprophylaxis administration. Thromboprophylaxis administration was not associated with surgical site infection (0.9% vs 0.6%; odds ratio, 1.48; 95% confidence interval, 0.80-2.74), bleeding complications (0.2% vs 0.1%; odds ratio, 2.60; 95% confidence interval, 0.99-6.80), or postpartum readmission (0.9% vs 0.3%; adjusted odds ratio, 1.38; 95% confidence interval, 0.68-2.81). The overall rate of venous thromboembolism was 0.06% (95% confidence interval, 0.03%-0.10%) and was higher in those receiving prophylaxis (0.2%) compared with those not receiving prophylaxis (0.04%).

CONCLUSION

Approximately 1 in 10 patients received postpartum pharmacologic thromboprophylaxis in this US cohort. Rates of prophylaxis varied widely by institution. Cesarean delivery, hysterectomy, and obesity were predominant factors associated with postpartum thromboprophylaxis administration.

Application of desirability of outcome ranking to the milking in non-vigorous infants trial

OBJECTIVES

Neonatal trials have traditionally used binary composite short-term (such as death or bronchopulmonary dysplasia) or longer-term (such as death or severe neurodevelopmental impairment) outcomes. We applied the Desirability Of Outcome Ranking (DOOR) method to rank the overall patient outcome by best (no morbidities) to worst (death).

STUDY DESIGN

Using a completed large multicenter trial (Milking In Non-Vigorous Infants [MINVI]) of umbilical cord milking (UCM) vs. early cord clamping (ECC), we applied the DOOR methodology to neonatal outcomes. Six outcomes were chosen and ranked: no interventions or NICU admission (most desirable); received initial cardiorespiratory support at birth; neonatal intensive care unit (NICU) admission for predefined criteria; mild hypoxic-ischemic encephalopathy (HIE); moderate to severe HIE; and death (least desirable).

RESULTS

1524 non-vigorous newborns born between 35 and 42 weeks' gestation had data for analysis. The DOOR distribution was different between the UCM and ECC arms, with a significantly greater probability (55.8 % [95 % CI 53.1-58.5 %; p < 0.0001]) of a randomly selected neonate having a more desirable outcome if they were in the UCM arm. DOOR probabilities of averting individual adverse outcomes such as NICU admission for predefined criteria (52.8 %; 95%CI 50.5-55.1 %) and cardiorespiratory support (54.0 %; 95%CI 51.6-56.4 %) were significantly higher among those in the UCM group.

CONCLUSION

DOOR provides an overall assessment of the benefits and harms with greater insight than typical binary composite measures to clinicians and parents when evaluating an intervention. Future neonatal trials should consider the a priori use of the DOOR methodology to evaluate trial outcomes.

Nutritional Intake in Dichorionic Twin Pregnancies: A Descriptive Analysis of a Multisite United States Cohort

INTRODUCTION

Twin gestations have greater nutritional demands than singleton gestations, yet dietary intakes of women with twin gestations have not been well described.

METHODS

In a prospective, multi-site US study of 148 women with dichorionic twin gestations (2012-2013), we examined longitudinal changes in diet across pregnancy. Women completed a food frequency questionnaire during each trimester of pregnancy. We examined changes in means of total energy and energy-adjusted dietary components using linear mixed effects models.

RESULTS

Mean energy intake (95% CI) across the three trimesters was 2010 kcal/day (1846, 2175), 2177 kcal/day (2005, 2349), 2253 kcal/day (2056, 2450), respectively (P = 0.01), whereas the Healthy Eating Index-2010 was 63.9 (62.1, 65.6), 64.5 (62.6, 66.3), 63.2 (61.1, 65.3), respectively (P = 0.53).

DISCUSSION

Women with twin gestations moderately increased total energy as pregnancy progressed, though dietary composition and quality remained unchanged. These findings highlight aspects of nutritional intake that may need to be improved among women carrying twins.

Social determinants of health and obstetric outcomes: A report and recommendations of the workshop of the Society for Maternal-Fetal Medicine

This article is a report of a 2-day workshop, entitled "Social determinants of health and obstetric outcomes," held during the Society for Maternal-Fetal Medicine 2022 Annual Pregnancy Meeting. Participants' fields of expertise included obstetrics, pediatrics, epidemiology, health services, health equity, community-based research, and systems biology. The Commonwealth Foundation and the Alliance of Innovation on Maternal Health cosponsored the workshop and the Society for Women's Health Research provided additional support. The workshop included presentations and small group discussions, and its goals were to accomplish the following.

Community-level social determinants of health and pregestational and gestational diabetes

BACKGROUND

Individual adverse social determinants of health are associated with increased risk of diabetes in pregnancy, but the relative influence of neighborhood or community-level social determinants of health is unknown.

OBJECTIVE

This study aimed to determine whether living in neighborhoods with greater socioeconomic disadvantage, food deserts, or less walkability was associated with having pregestational diabetes and developing gestational diabetes.

STUDY DESIGN

We conducted a secondary analysis of the prospective Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-To-Be. Home addresses in the first trimester were geocoded at the census tract level. The exposures (modeled separately) were the following 3 neighborhood-level measures of adverse social determinants of health: (1) socioeconomic disadvantage, defined by the Area Deprivation Index and measured in tertiles from the lowest tertile (ie, least disadvantage [T1]) to the highest (ie, most disadvantage [T3]); (2) food desert, defined by the United States Department of Agriculture Food Access Research Atlas (yes/no by low income and low access criteria); and (3) less walkability, defined by the Environmental Protection Agency National Walkability Index (most walkable score [15.26-20.0] vs less walkable score [<15.26]). Multinomial logistic regression was used to model the odds of gestational diabetes or pregestational diabetes relative to no diabetes as the reference, adjusted for age at delivery, chronic hypertension, Medicaid insurance status, and low household income (<130% of the US poverty level).

RESULTS

Among the 9155 assessed individuals, the mean Area Deprivation Index score was 39.0 (interquartile range, 19.0-71.0), 37.0% lived in a food desert, and 41.0% lived in a less walkable neighborhood. The frequency of pregestational and gestational diabetes diagnosis was 1.5% and 4.2%, respectively. Individuals living in a community in the highest tertile of socioeconomic disadvantage had increased odds of entering pregnancy with pregestational diabetes compared with those in the lowest tertile (T3 vs T1: 2.6% vs 0.8%; adjusted odds ratio, 2.52; 95% confidence interval, 1.41-4.48). Individuals living in a food desert (4.8% vs 4.0%; adjusted odds ratio, 1.37; 95% confidence interval, 1.06-1.77) and in a less walkable neighborhood (4.4% vs 3.8%; adjusted odds ratio, 1.33; 95% confidence interval, 1.04-1.71) had increased odds of gestational diabetes. There was no significant association between living in a food desert or a less walkable neighborhood and pregestational diabetes, or between socioeconomic disadvantage and gestational diabetes.

CONCLUSION

Nulliparous individuals living in a neighborhood with higher socioeconomic disadvantage were at increased odds of entering pregnancy with pregestational diabetes, and those living in a food desert or a less walkable neighborhood were at increased odds of developing gestational diabetes, after controlling for known covariates.

Racial disparities in the selection of chief resident: A cross-sectional analysis of a national sample of senior residents in the United States

INTRODUCTION

Part of the difficulty in recruiting and retaining a diverse physician workforce, as well as within medical leadership, is due to racial disparities in medical education. We investigated whether self-identified race-ethnicity is associated with the likelihood of selection as chief resident (CR).

MATERIALS AND METHODS

We performed a cross sectional analysis using de-identified person-level data from the GME Track, a national resident database and tracking system, from 2015 through 2018. The exposure variable, self-identified race-ethnicity, was categorized as African American or Black, American Indian or Alaskan Native, Asian, Hispanic, Latino or of Spanish Origin, Native Hawaiian or Pacific Islander, White, and Multi-racial. The primary study outcome was CR selection among respondents in their final program year. Logistic regression was used to estimate the adjusted odds ratios (aOR) and 95% confidence intervals (CI) of CR selection for each racial group, as compared to the White referent group.

RESULTS

Among the study population (N=121,247), Black, Asian and Hispanic race-ethnicity was associated with a significantly decreased odds of being selected as CR in unadjusted and adjusted analyses. Black, Asian and Hispanic residents had a 26% (aOR=0.74, 95% CI 0.66-0.83), 29% (aOR=0.71, 95% CI 0.66-0.76) and 28% (aOR=0.72, 95% CI 0.66-0.94) decreased likelihood of becoming CR, respectively. Multi-racial residents also had a decreased likelihood, but to a lesser degree (aOR=0.92, 95% CI 0.89-0.95).

CONCLUSIONS

In as much as CR is an honor that sets one up for future opportunity, our findings suggest that residents of color are disproportionately disadvantaged compared to their White peers.

The use of adjunctive mechanical dilation at the time of induction termination and adverse health outcomes: a systematic review

OBJECTIVE

This study aimed to assess if the use of mechanical dilation at the time of induction termination is associated with changes in the time from initiation of labor to expulsion of the fetus (induction-to-expulsion interval) and with the frequency of health complications when compared with medication management alone.

DATA SOURCES

PubMed, CINAHAL, Scopus, and the Cochrane Central Register of Controlled Trials were queried from January 2000 to May 2023.

STUDY ELIGIBILITY CRITERIA

We included randomized controlled trials of individuals who were assigned to undergo mechanical dilation (ie, laminaria, Dilapan-S, and intracervical Foley balloon catheter) in combination with the use of medication and compared it with the outcomes of medication use (eg, prostaglandins, antiprogestins, oxytocin) alone.

METHODS

The primary outcome was the induction-to-expulsion interval. The secondary outcomes were the incidence of clinical chorioamnionitis, sepsis, hemorrhage, the need for blood transfusion and uterotonics, cervical laceration, the need for adjunctive procedures (eg, dilation and curettage), failed induction termination, uterine rupture, intensive care unit admission, or death. Assessment of bias was performed using the Cochrane Risk of Bias tool. A subgroup analysis was performed among studies deemed to be at low risk of bias.

RESULTS

Of 864 abstracts identified, 11 met the inclusion criteria. Five studies demonstrated a shorter induction-to-expulsion interval among those randomized to mechanical dilation, whereas 6 studies demonstrated a similar or longer induction-to-expulsion interval. There were no significant differences reported in the frequency of any adverse outcomes between the trial arms. In addition, most studies (8/11) exhibited moderate to high levels of bias. In an analysis of the 3 studies deemed to have a low risk of bias, 1 (n=60) demonstrated a longer induction-to-expulsion interval with adjunctive laminaria, 1 (n=60) demonstrated a shorter induction-to-expulsion interval with adjunctive intracervical Foley balloon catheter use, and 1 demonstrated no difference in the induction-to-expulsion interval with adjunctive Dilapan-S use (n=180).

CONCLUSION

Only a small number of studies, most of which were of low quality, assessed mechanical dilation for induction termination. The results of these studies were inconsistent in terms of the induction-to-expulsion interval of adjunctive mechanical methods in comparison with medication management alone. Studies did not reveal significant differences between the groups in adverse outcomes. Further research should investigate the use of mechanical dilation at the time of induction termination using high-quality methods.

Mapping the Postpartum Experience Through Obstetric Patient Navigation for Low-Income Individuals

Background: Although the postpartum period is an opportunity to address long-term health, fragmented care systems, inadequate attention to social needs, and a lack of structured transition to primary care threaten patient wellbeing, particularly for low-income individuals. Postpartum patient navigation is an emerging innovation to address these disparities. Methods: This mixed-methods analysis uses data from the first year of an ongoing randomized controlled trial to understand the needs of low-income postpartum individuals through 1 year of patient navigation. We designed standardized logs for navigators to record their services, tracking mode, content, intensity, and target of interactions. Navigators also completed semistructured interviews every 3 months regarding relationships with patients and care teams, care system gaps, and navigation process. Log data were categorized, quantified, and mapped temporally through 1 year postpartum. Qualitative data were analyzed using the constant comparative method. Results: Log data from 50 participants who received navigation revealed the most frequent needs related to health care access (45.4%), health and wellness (18.2%), patient-navigator relationship building (14.8%), parenting (13.6%), and social determinants of health (8.0%). Navigation activities included supporting physical and mental recovery, accomplishing health goals, connecting patients to primary and specialty care, preparing for health system utilization beyond navigation, and referring individuals to community resources. Participant needs fluctuated, yielding a dynamic timeline of the first postpartum year. Conclusion: Postpartum needs evolved throughout the year, requiring support from various teams. Navigation beyond the typical postpartum care window may be useful in mitigating health system barriers, and tracking patient needs may be useful in optimizing postpartum care. Clinical Trial Registration: Registered April 19, 2019, enrollment beginning January 21, 2020, NCT03922334, https://clinicaltrials.gov/ct2/show/NCT03922334.

Perinatal morbidity among women with a previous caesarean delivery (PRISMA trial): a cluster-randomised trial

BACKGROUND

Women with a previous caesarean delivery face a difficult choice in their next pregnancy: planning another caesarean or attempting vaginal delivery, both of which are associated with potential maternal and perinatal complications. This trial aimed to assess whether a multifaceted intervention, which promoted person-centred decision making and best practices, would reduce the risk of major perinatal morbidity among women with one previous caesarean delivery.

METHODS

We conducted an open, multicentre, cluster-randomised, controlled trial of a multifaceted 2-year intervention in 40 hospitals in Quebec among women with one previous caesarean delivery, in which hospitals were the units of randomisation and women the units of analysis. Randomisation was stratified according to level of care, using blocked randomisation. Hospitals were randomly assigned (1:1) to the intervention group (implementation of best practices and provision of tools that aimed to support decision making about mode of delivery, including an estimation of the probability of vaginal delivery and an ultrasound estimation of the risk of uterine rupture), or the control group (no intervention). The primary outcome was a composite risk of major perinatal morbidity. This trial was registered with ISRCTN, ISRCTN15346559.

FINDINGS

21 281 eligible women delivered during the study period, from April 1, 2016 to Dec 13, 2019 (10 514 in the intervention group and 10 767 in the control group). None were lost to follow-up. There was a significant reduction in the rate of major perinatal morbidity from the baseline period to the intervention period in the intervention group as compared with the control group (adjusted odds ratio [OR] for incremental change over time, 0·72 [95% CI 0·52-0·99]; p=0·042; adjusted risk difference -1·2% [95% CI -2·0 to -0·1]). Major maternal morbidity was significantly reduced in the intervention group as compared with the control group (adjusted OR 0·54 [95% CI 0·33-0·89]; p=0·016). Minor perinatal and maternal morbidity, caesarean delivery, and uterine rupture rates did not differ significantly between groups.

INTERPRETATION

A multifaceted intervention supporting women in their choice of mode of delivery and promoting best practices resulted in a significant reduction in rates of major perinatal and maternal morbidity, without an increase in the rate of caesarean or uterine rupture.

FUNDING

Canadian Institutes of Health Research (CIHR, MOP-142448).

Racial and Ethnic Disparities in Receipt of General Anesthesia for Cesarean Delivery

Importance

General anesthesia for cesarean delivery is associated with increased maternal morbidity, and Black and Hispanic pregnant patients have higher rates of general anesthesia use compared with their non-Hispanic White counterparts. It is unknown whether risk factors and indications for general anesthesia differ among patients of differing race and ethnicity.

Objective

To evaluate differences in general anesthesia use for cesarean delivery and the indication for the general anesthetic by race and ethnicity.

Design, Setting, and Participants

In this retrospective, cross-sectional, single-center study, electronic medical records for all 35 117 patients who underwent cesarean delivery at Northwestern Medicine's Prentice Women's Hospital from January 1, 2007, to March 2, 2018, were queried for maternal demographics, clinical characteristics, obstetric and anesthetic data, the indication for cesarean delivery, and the indication for general anesthesia when used. Data analysis occurred in August 2023.

Exposure

Cesarean delivery.

Main Outcomes and Measures

The rate of general anesthesia for cesarean delivery by race and ethnicity.

Results

Of the 35 117 patients (median age, 33 years [IQR, 30-36 years]) who underwent cesarean delivery, 1147 (3.3%) received general anesthesia; the rates of general anesthesia were 2.5% for Asian patients (61 of 2422), 5.0% for Black patients (194 of 3895), 3.7% for Hispanic patients (197 of 5305), 2.8% for non-Hispanic White patients (542 of 19 479), and 3.8% (153 of 4016) for all other groups (including those who declined to provide race and ethnicity information) (P < .001). A total of 19 933 pregnant patients (56.8%) were in labor at the time of their cesarean delivery. Of those, 16 363 (82.1%) had neuraxial labor analgesia in situ. Among those who had an epidural catheter in situ, there were no racial or ethnic differences in the rates of general anesthesia use vs neuraxial analgesia use (Asian patients, 34 of 503 [6.8%] vs 1289 of 15 860 [8.1%]; Black patients, 78 of 503 [15.5%] vs 1925 of 15 860 [12.1%]; Hispanic patients, 80 of 503 [15.9%] vs 2415 of 15 860 [15.2%]; non-Hispanic White patients, 255 of 503 [50.7%] vs 8285 of 15 860 [52.2%]; and patients of other race or ethnicity, 56 of 503 [11.1%] vs 1946 of 15 860 [12.3%]; P = .16). Indications for cesarean delivery and for general anesthesia were not different when stratified by race and ethnicity.

Conclusions and Relevance

Racial disparities in rates of general anesthesia continue to exist; however, this study suggests that, for laboring patients who had labor epidural catheters in situ, no disparity by race or ethnicity existed. Future studies should address whether disparities in care that occur prior to neuraxial catheter placement are associated with higher rates of general anesthesia among patients from ethnic and racial minority groups.