Medically indicated preterm birth: recognizing the importance of the problem

Ischemic Placental Disease: Epidemiology and Impact on Maternal and Offspring Health Along the Life Course

Ischemic placental disease (IPD) is a constellation of obstetrical complications that include preeclampsia, placental abruption, and fetal growth restriction and affects 12% to 15% of pregnancies. The unifying pathophysiological mechanism that precedes all 3 complications is uteroplacental ischemia as a consequence of inadequate (or failure of) physiological transformation of the maternal uterine spiral arteries, endothelial cell dysfunction, and increased oxidative stress. This review summarizes the IPD literature, focusing on the epidemiology and risk factors, the effects of IPD on short and long-term maternal complications, and the association of IPD with perinatal, childhood, and long-term complications in offspring.

Predictors of Inflammation-Mediated Preterm Birth

Preterm birth remains a worldwide health concern because of ongoing challenges in prediction and prevention. Current predictors are limited by poor performance, need for invasive sampling, and an inability to identify patients in a timely fashion to allow for effective intervention. The multiple etiologies of preterm birth often have an inflammatory component. Thus, a deeper understanding of the inflammatory mechanisms involved in preterm birth may provide opportunities to identify new predictors of preterm birth. This review discusses the multiple etiologies of preterm birth, their links to inflammation, current predictors available, and new directions for the field.

Fine Particulate Matter, Its Constituents, and Spontaneous Preterm Birth

Importance

The associations of exposure to fine particulate matter (PM2.5) and its constituents with spontaneous preterm birth (sPTB) remain understudied. Identifying subpopulations at increased risk characterized by socioeconomic status and other environmental factors is critical for targeted interventions.

Objective

To examine associations of PM2.5 and its constituents with sPTB.

Design, Setting, and Participants

This population-based retrospective cohort study was conducted from 2008 to 2018 within a large integrated health care system, Kaiser Permanente Southern California. Singleton live births with recorded residential information of pregnant individuals during pregnancy were included. Data were analyzed from December 2023 to March 2024.

Exposures

Daily total PM2.5 concentrations and monthly data on 5 PM2.5 constituents (sulfate, nitrate, ammonium, organic matter, and black carbon) in California were assessed, and mean exposures to these pollutants during pregnancy and by trimester were calculated. Exposures to total green space, trees, low-lying vegetation, and grass were estimated using street view images. Wildfire-related exposure was measured by the mean concentration of wildfire-specific PM2.5 during pregnancy. Additionally, the mean exposure to daily maximum temperature during pregnancy was calculated.

Main Outcomes and Measures

The primary outcome was sPTB identified through a natural language processing algorithm. Discrete-time survival models were used to estimate associations of total PM2.5 concentration and its 5 constituents with sPTB. Interaction terms were used to examine the effect modification by race and ethnicity, educational attainment, household income, and exposures to green space, wildfire smoke, and temperature.

Results

Among 409 037 births (mean [SD] age of mothers at delivery, 30.3 [5.8] years), there were positive associations of PM2.5, black carbon, nitrate, and sulfate with sPTB. Adjusted odds ratios (aORs) per IQR increase were 1.15 (95% CI, 1.12-1.18; P < .001) for PM2.5 (IQR, 2.76 μg/m3), 1.15 (95% CI, 1.11-1.20; P < .001) for black carbon (IQR, 1.05 μg/m3), 1.09 (95% CI, 1.06-1.13; P < .001) for nitrate (IQR, 0.93 μg/m3), and 1.06 (95% CI, 1.03-1.09; P < .001) for sulfate (IQR, 0.40 μg/m3) over the entire pregnancy. The second trimester was the most susceptible window; for example, aORs for total PM2.5 concentration were 1.07 (95% CI, 1.05-1.09; P < .001) in the first, 1.10 (95% CI, 1.08-1.12; P < .001) in the second, and 1.09 (95% CI, 1.07-1.11; P < .001) in the third trimester. Significantly higher aORs were observed among individuals with lower educational attainment (eg, less than college: aOR, 1.16; 95% CI, 1.12-1.21 vs college [≥4 years]: aOR, 1.10; 95% CI, 1.06-1.14; P = .03) or income (<50th percentile: aOR, 1.17; 95% CI, 1.14-1.21 vs ≥50th percentile: aOR, 1.12; 95% CI, 1.09-1.16; P = .02) or who were exposed to limited green space (<50th percentile: aOR, 1.19; 95% CI, 1.15-1.23 vs ≥50th percentile: aOR, 1.12; 95% CI, 1.09-1.15; P = .003), more wildfire smoke (≥50th percentile: aOR, 1.19; 95% CI, 1.16-1.23 vs <50th percentile: aOR, 1.13; 95% CI, 1.09-1.16; P = .009), or extreme heat (aOR, 1.51; 95% CI, 1.42-1.59 vs mild temperature: aOR, 1.11; 95% CI, 1.09-1.14; P < .001).

Conclusions and Relevance

In this study, exposures to PM2.5 and specific PM2.5 constituents during pregnancy were associated with increased odds of sPTB. Socioeconomic status and other environmental exposures modified this association.

Does the use of angiogenic biomarkers for the management of preeclampsia and fetal growth restriction improve outcomes?: Challenging the current status quo

Monitoring and timing of delivery in preterm preeclampsia and fetal growth restriction is one of the biggest challenges in Obstetrics. Finding the optimal time of delivery of these fetuses usually involves a trade-off between the severity of the disease and prematurity. So far, most clinical guidelines recommend the use of a combination between clinical, laboratory and ultrasound markers to guide the time of delivery. Angiogenic biomarkers, especially placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1), have gained significant attention in recent years for their potential role in the prediction and diagnosis of placenta-related disorders including preeclampsia and fetal growth restriction. Another potential clinical application of the angiogenic biomarkers is for the differential diagnosis of patients with chronic kidney disease, as this condition shares similar clinical features with preeclampsia. Consequently, angiogenic biomarkers have been advocated as tools for monitoring and deciding the optimal time of the delivery of fetuses affected by placental dysfunction. In this clinical opinion, we critically review the available literature on PlGF and sFlt-1 for the surveillance and time of the delivery in fetuses affected by preterm preeclampsia and fetal growth restriction. Moreover, we explore the use of angiogenic biomarkers for the differentiation between chronic kidney disease and superimposed preeclampsia.

Validation of parental recall questionnaire to classify preterm delivery subtypes: Spontaneous preterm labour, preterm premature rupture of membranes and clinician-initiated preterm delivery

BACKGROUND

Preterm delivery (PTD) includes three main presenting subtypes: spontaneous preterm labour (sPTL), preterm premature rupture of membranes (pPROM) and clinician-initiated preterm delivery (ciPTD). PTD subtype data are rarely available from birth registries and are onerous to derive from medical records.

OBJECTIVES

To develop and test the validity of a questionnaire to classify PTD subtype based on birthing parent recall of labour and delivery events.

METHODS

The questionnaire was sent in 2022 to 581 patients with PTD history documented in the LIFECODES study, a hospital-based birth cohort in Boston, Massachusetts. Eighty-two respondents reported 94 PTDs that could be linked to medical records. Data on PTD subtype were extracted from medical records as the reference standard.

RESULTS

Medical records indicated 47 spontaneous (24 sPTL, 23 pPROM) and 47 ciPTD deliveries occurring a median eight years earlier. The sensitivity and specificity of the recall questionnaire were 88% (95% confidence interval: 68, 97%) and 89% (79, 95%) for sPTL; 96% (78, 100%) and 94% (86, 98%) for pPROM; and 83% (69, 92%) and 100% (92, 100%) for ciPTD, respectively. Greater time since pregnancy did not degrade the sensitivity or specificity of the parental recall questionnaire.

CONCLUSIONS

Although derived from a modest sample, the moderate-to-high sensitivity and specificity of the parental recall questionnaire to classify sPTL, pPROM and ciPTD demonstrates its potential for large studies of PTD and for correction of misclassification bias. Future studies are required to test the questionnaire in a variety of populations.

PREPARE: A Stepped-Wedge Cluster-Randomized Trial to Evaluate Whether Risk Stratification Can Reduce Preterm Deliveries Among Patients With Suspected or Confirmed Preterm Preeclampsia

BACKGROUND

Early delivery in preterm preeclampsia may reduce the risks for the patient, but consequences of prematurity may be substantial for the baby. This trial evaluated whether the implementation of a risk stratification model could safely reduce prematurity.

METHODS

This was a stepped-wedge cluster-randomized trial in seven clusters. Patients presenting with suspected or confirmed preeclampsia between 20+0 and 36+6 gestational weeks were considered eligible. At the start of the trial, all centers were allocated in the preintervention phase, and patients enrolled in this phase were managed according to local treatment guidance. Subsequently, every 4 months, 1 randomly allocated cluster transitioned to the intervention. Patients enrolled in the intervention phase had sFlt-1 (soluble fms-like tyrosine kinase-1)/PlGF (placental growth factor) ratio and preeclampsia integrated estimate of risk assessments performed. If sFlt-1/PlGF ≤38 and preeclampsia integrated estimate of risk <10%, patients were considered low risk and clinicians received recommendations to defer delivery. If sFlt-1/PlGF >38 and preeclampsia integrated estimate of risk ≥10%, patients were considered not low risk, and clinicians received recommendations to increase surveillance. The primary outcome was the proportion of patients with preterm preeclampsia delivered prematurely out of total deliveries.

RESULTS

Between March 25, 2017 and December 24, 2019, 586 and 563 patients were analyzed in the intervention and usual care groups, respectively. The event rate was 1.09% in the intervention group, and 1.37% in the usual care group. After prespecified adjustments for variation between and within clusters over time, the adjusted risk ratio was 1.45 ([95% CI, 1.04-2.02]; P=0.029), indicating a higher risk of preterm deliveries in the intervention group. Post hoc analysis including calculation of risk differences did not show evidence of statistical differences. Abnormal sFlt-1/PlGF was associated with a higher rate of identifying preeclampsia with severe features.

CONCLUSIONS

The introduction of an intervention based on biomarkers and clinical factors for risk stratification did not lead to reductions in preterm deliveries. Further training on the interpretation of disease severity in preeclampsia and the development of additional risk stratification is needed before adoption into clinical practice.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT03073317.

Pregnancy and neonatal outcomes among women with early-onset colorectal cancer: a nationwide case-control study

Background

Early-onset colorectal cancer has risen worldwide, leaving more women with colorectal cancer at reproductive ages. We aimed to investigate the risk of adverse pregnancy and neonatal outcomes among women with early-onset colorectal cancer.

Methods

We conducted a nationwide, matched case-control study of maternal/pregnancy outcomes including pre-eclampsia and Cesarean delivery (C-section) as well as neonatal outcomes including preterm birth among 207 births in women with early-onset colorectal cancer (ages 18-49) and 1019 births in women without colorectal cancer in Sweden (1992-2019). Early-onset colorectal cancer cases were identified through the Cancer Register, and outcome data were retrieved through linkage to Medical Birth Register and National Patient Register. Using conditional logistic regression, we estimated multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs).

Findings

Between Jan 1, 1992, and Dec 31, 2019, women with early-onset colorectal cancer who gave birth had increased odds of pre-eclampsia (7.2% vs 3.2%; OR = 2.52, 95%CI = 1.25-5.08), any C-section (24.6% vs 19.4%; OR = 1.43, 95%CI = 1.00-2.06), particularly emergency C-section (17.4% vs 10.5%; OR = 1.79, 95%CI = 1.17-2.75), after adjustment for maternal education level, country of birth, body mass index and smoking in early pregnancy, and comorbidities. Maternal history of early-onset colorectal cancer was also associated with offspring preterm birth (12.1% vs 5.2%; OR = 2.31, 95%CI = 1.34-3.99), delineated as spontaneous (OR = 1.06, 95%CI = 0.47-2.39) or medically-indicated preterm birth (OR = 4.48, 95%CI = 2.05-9.79). There was no increased risk of congenital malformation or small for gestational age birth.

Interpretation

In this population-based study, maternal history of early-onset colorectal cancer was associated with risk of both adverse pregnancy (pre-eclampsia, C-section) and neonatal outcomes (preterm birth).

Funding

US National Institutes of Health, Swedish Society of Medicine, Swedish Cancer Foundation.

An exploratory analysis of factors associated with spontaneous preterm birth among pregnant veterans with post-traumatic stress disorder

BACKGROUND

Pregnant veterans with post-traumatic stress disorder (PTSD) are at increased risk for spontaneous preterm birth, yet the underlying reasons are unclear. We examined factors associated with spontaneous preterm birth among pregnant veterans with active PTSD.

METHODS

This was an observational study of births from administrative databases reimbursed by the Veterans Health Association (VA) between 2005 and 2015. Singleton livebirths among veterans with active PTSD within 12 months prior to childbirth were included. The primary outcome was spontaneous preterm birth. Maternal demographics, psychiatric history, and pregnancy complications were evaluated as exposures. Covariates significant on bivariate analysis, as well as age and race/ethnicity as a social construct, were included in multivariable logistic regression to identify factors associated with spontaneous preterm birth. Additional analyses stratified significant covariates by the presence of active concurrent depression and explored interactions between antidepressant use and preeclampsia.

RESULTS

Of 3,242 eligible births to veterans with active PTSD, 249 (7.7%) were spontaneous preterm births. The majority of veterans with active PTSD (79.1%) received some type of mental health treatment, and active concurrent depression was prevalent (61.4%). Preeclampsia/eclampsia (adjusted odds ratio [aOR] 3.30, 95% confidence interval [CI] 1.67-6.54) and ≥6 antidepressant medication dispensations within 12 months prior to childbirth (aOR 1.89, 95% CI 1.29-2.77) were associated with spontaneous preterm birth. No evidence of interaction was seen between antidepressant use and preeclampsia on spontaneous preterm birth (p=0.39). Findings were similar when stratified by active concurrent depression.

CONCLUSION

Among veterans with active PTSD, preeclampsia/eclampsia and ≥6 antidepressant dispensations were associated with spontaneous preterm birth. While the results do not imply that people should discontinue needed antidepressants during pregnancy in veterans with PTSD, research into these factors might inform preterm birth prevention strategies for this high-risk population.

Trial of Intrapartum Extended-Release Nifedipine to Prevent Severe Hypertension Among Pregnant Individuals With Preeclampsia With Severe Features

BACKGROUND

Preeclampsia is associated with maternal and perinatal morbidity. Besides acute therapy for severe hypertension, best practices are lacking for intrapartum hypertension management. Our objective was to test the hypothesis that intrapartum initiation of extended-release nifedipine in individuals with preeclampsia with severe features prevents severe hypertension.

METHODS

Randomized, triple-blind, placebo-controlled trial of individuals with preeclampsia with severe features undergoing labor induction between 22^0/7 and 41^6/7 weeks gestation. Participants were randomized to oral extended-release nifedipine 30 mg or identical placebo every 24 hours. Primary outcome is defined as receipt of ≥1 dose of acute hypertension therapy for severe blood pressure (≥160/110 mm Hg) sustained ≥10 minutes. Secondary outcomes included route of delivery, neonatal intensive care unit admission, and a composite of adverse neonatal outcomes.

RESULTS

Of 365 individuals screened, 55 were randomized to nifedipine and 55 to placebo. Primary outcome was observed in 34.0% of individuals in nifedipine group versus 55.1% in placebo group (relative risk [RR] 0.62 [95% CI, 0.39-0.97]); number needed to treat to prevent receipt of acute treatment was 4.7 (95% CI, 2.5-44.3). Fewer individuals in nifedipine group required cesarean delivery compared with placebo group (20.8% versus 34.7%, RR, 0.60 [95% CI, 0.31-1.15]). Neonatal intensive care unit admission rate was lower in nifedipine group compared with placebo (29.1% versus 47.1%; RR 0.62 [95% CI, 0.37-1.02]). Neonatal composite was similar between groups (35.8% versus 41.2%, RR, 0.83 [95% CI, 0.51-1.37]).

CONCLUSIONS

Initiation of extended-release nifedipine is effective in reducing intrapartum acute hypertensive therapy among individuals with preeclampsia with severe features.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04392375.

Understanding Etiologic Pathways Through Multiple Sequential Mediators: An Application in Perinatal Epidemiology

BACKGROUND

Causal mediation analysis facilitates decomposing the total effect into a direct effect and an indirect effect that operates through an intermediate variable. Recent developments in causal mediation analysis have clarified the process of evaluating how-and to what extent-different pathways via multiple causally ordered mediators link the exposure to the outcome.

METHODS

Through an application of natural effect models for multiple mediators, we show how placental abruption might affect perinatal mortality using small for gestational age (SGA) birth and preterm delivery as two sequential mediators. We describe methods to disentangle the total effect into the proportions mediated via each of the sequential mediators, when evaluating natural direct and natural indirect effects.

RESULTS

Under the assumption that SGA births causally precedes preterm delivery, an analysis of 16.7 million singleton pregnancies is consistent with the hypothesis that abruption exerts powerful effects on perinatal mortality (adjusted risk ratio = 11.9; 95% confidence interval = 11.6, 12.1). The proportions of the estimated total effect mediated through SGA birth and preterm delivery were 2% and 58%, respectively. The proportion unmediated via either SGA or preterm delivery was 41%.

CONCLUSIONS

Through an application of causal mediation analysis with sequential mediators, we uncovered new insights into the pathways along which abruption impacts perinatal mortality.

Optimal annual body mass index change for preventing spontaneous preterm birth in a subsequent pregnancy

Preterm birth (PTB) is a leading cause of neonatal morbidity and mortality. Although PTB is known to recur, interpregnancy preventive strategies for PTB have not been established to date. Annual BMI change can serve as a specific target value for preventing obstetric complications during interpregnancy care/counseling. This value can also account for age-related weight gain (0.2 kg/m²/year). In a multicenter retrospective study, we investigated the optimal annual BMI change for preventing PTB recurrence using the data of individuals who had two singleton births from 2009 to 2019. The association between annual BMI change and spontaneous PTB (sPTB) was analyzed by separating cases of medically indicated PTB (mPTB) from those of sPTB. Previous history of sPTB was strongly associated with sPTB in the subsequent pregnancy (adjusted odds ratio [aOR], 12.7; 95% confidence interval [CI], 6.5-24.8). Increase in annual BMI was negatively associated with sPTB (aOR, 0.6; 95% CI 0.5-0.9). The sPTB recurrence rate was significantly lower in patients with an annual BMI change of ≥ 0.25 kg/m²/year than in those with an annual BMI change of < 0.25 kg/m²/year (7.7% vs. 35.0%, p = 0.011). Our findings suggest that age-related annual BMI gain between pregnancies may help prevent sPTB recurrence.

Predicting preterm birth based on vaginal microbiota assessment by real-time PCR in the first trimester

Detecting high risk of preterm birth (PB) early makes its prevention possible. The aim of the work was to develop a mathematical predictive model for assessing the risk of preterm birth based on a quantitative analysis of the vaginal microbiota in the first trimester of pregnancy. The study included 199 pregnant women, i.e. 41 pregnancies that ended in preterm birth, and 158 — in term birth. Vaginal microbiota was analyzed in all patients in the 1st trimester of pregnancy by quantitative real-time PCR (qPCR). The method of dicriminant analysis was used to develop a predictive model. A method for predicting PB was developed with the calculation of the PRIMA prognostic index (Premature Birth. Index Of Microbiological Analysis). If the value of PRIMA > 0 – the risk of premature birth is low, if PRIMA < 0 – the risk is high. The sensitivity and specificity of the method are respectively 70.7% and 79.75%, the effectiveness is 77.89%. Evaluation of vaginal microbiota in the 1st trimester makes it possible to identify a high-risk group of PB and perform timely preventive measures.

Interferon epsilon and preterm birth subtypes; a new piece of the type I interferon puzzle during pregnancy?

PROBLEM

Interferon epsilon (IFNε) is a unique type I IFN that is expressed in response to sex steroids. Studies suggest that type I IFNs regulate inflammation-induced preterm birth (PTB), but no study has examined the role of IFNε in human pregnancy.

METHOD OF STUDY

We used stored vaginal swabs between 8 and 26 weeks of gestation from the Global Alliance to Prevent Prematurity and Stillbirth (GAPPS) biobank and measured IFNε by enzyme-linked immunosorbent assay (ELISA). A total of 29 women with spontaneous preterm births, 34 women with medically indicated preterm births, and 134 women with term births were included. Secondary outcomes included a preterm birth with chorioamnionitis and preeclampsia with a preterm birth. Logistic regression calculated odds ratios (OR) and 95% confidence intervals (CI) adjusting for maternal age, race, body mass index, prior pregnancy complications, lower genital tract infections, chronic health conditions, and gestational age at blood draw.

RESULTS AND CONCLUSIONS

There was no significant association between IFNε and spontaneous preterm birth (OR_adj 1.0, 0.8-1.3) or chorioamnionitis (OR_adj 1.6, 0.7-3.5). A trend toward increased odds of medically indicated preterm birth (OR_adj . 1.3, 1.0-1.8) was observed. This was likely due to elevated IFNε among women with preterm preeclampsia (OR_adj . 2.0, 95% CI 1.3-3.2). While exploratory, our novel findings suggest that larger longitudinal studies of IFNε across human pregnancy may be warranted.

Invited Commentary: Intermittent Opioid Use and Ischemic Placental Disease-Clarifying Associations With Adverse Pregnancy Outcomes

Discomfort and, to a lesser extent, pain are common complaints during pregnancy, and some patients may turn to opioids for pain relief. Esposito et al. (Am J Epidemiol. 2022;191(5):759-768) report associations between intermittent exposure to opioids during pregnancy and the risk of ischemic placental disease-a syndrome that includes preeclampsia, placental abruption, births that are small for gestational age, and preterm delivery. They found that early opioid exposure in pregnancy was associated with a modestly increased risk for abruption, births that are small for gestational age, and preterm delivery, and both early and late exposures were associated with the greatest risk for these outcomes. Surprisingly, preeclampsia was not associated with opioid use. Through quantitative bias analysis, the authors cleverly tackle a number of biases to assess their roles in explaining the associations, including unmeasured confounding, outcome misclassification, and residual confounding; none exerted strong influences on the associations. Although the findings appear fairly robust on the surface, the lack of association between intermittent opioid use and preeclampsia, and important differences in characteristics of patients in the opioid-exposed group compared with the unexposed group, suggest that further study is needed to clarify the relationship between intermittent opioid use, lifestyle factors, and ischemic placental disease risk.

A principled approach to mediation analysis in perinatal epidemiology

For many research questions in perinatal epidemiology, gestational age is a mediator that features the causal pathway between exposure and outcome. A mediator is an intermediate variable between an exposure and outcome, which is influenced by the exposure on the causal pathway to the outcome. Therefore, conventional analyses that adjust, stratify, or match for gestational age or its proxy (eg, preterm vs term deliveries) are problematic. This practice, which is entrenched in perinatal research, induces an overadjustment bias. Depending on the causal question, it may be inappropriate to adjust (or condition) for a mediator, such as gestational age, by either design or statistical analysis, but its effect can be quantified through causal mediation analysis. In an exposition of such methods, we demonstrated the relationship between the exposure and outcome and provided a formal analytical framework to quantify the extent to which a causal effect is influenced by a mediator. We reviewed concepts of confounding and causal inference, introduced the concept of a mediator and illustrated the perils of adjusting for a mediator in an exposure-outcome paradigm for a given causal question, adopted causal methods that call for an evaluation of a mediator in a causal exposure effect on the outcome, and discussed unmeasured confounding assumptions in mediation analysis. Furthermore, we reviewed other developments in the causal mediation analysis literature, including decomposition of a total effect when the mediator interacts with the exposure (4-way decomposition), methods for multiple mediators, mediation methods for case-control studies, mediation methods for time-to-event outcomes, sample size and power analysis for mediation analysis, and available software to apply these methods. To illustrate these methods, we provided a clinical example to estimate the risk of perinatal mortality (outcome) concerning placental abruption (exposure) and to determine the extent to which preterm delivery (mediator; a proxy for gestational age) plays a role in this causal effect. We hoped that the adoption of mediation methods described in this review will move research in perinatal epidemiology away from biased adjustments of mediators toward a more nuanced quantification of effects that pose unique challenges and provide unique insights in our field.

Endoscopic management of idiopathic subglottic stenosis in pregnancy

Aims

To describe the use of laser, endoscopic balloon dilatation with jet ventilation anaesthesia in the treatment of pregnant women with idiopathic subglottic stenosis.

Materials and methods

This is a case review of pregnant women with idiopathic subglottic stenosis, presenting to a tertiary referral centre with worsening breathlessness. Data were extracted from patient case notes.

Results

Four women underwent surgical management of subglottic stenosis in pregnancy. One patient required two procedures during the course of their pregnancy due to restenosis. All women had improvement in symptoms post-operatively and went on to deliver healthy babies at term.

Conclusion

Endoscopic balloon dilatation of idiopathic subglottic stenosis is a safe and viable treatment option in pregnancy and should be offered as first-line treatment in symptomatic women.

The effect of preexisting medical comorbidities on the preeclamptic phenotype: a retrospective cohort study

Objective:To compare the effect of comorbidities on the phenotype and outcomes of preeclampsia.Methods: A matched retrospective cohort study of women delivering at a tertiary maternity center following a diagnosis of preeclampsia. We collected data on signs and symptoms, biochemical markers, and maternal and perinatal outcomes.Results:We studied 474 women; 158 women with and 316 without comorbidities. Compared to women without comorbidities, women with comorbidities delivered earlier. They suffered fewer maternal but more neonatal complications.Conclusion: Women with comorbidities receive earlier intervention than women without comorbidities, which may lead to fewer maternal complications but worse neonatal outcomes.

Association between intimate partner violence during pregnancy and risk of preterm birth

Background

Preterm birth is a risk factor for child survival in both the short and long term. In Zimbabwe, the prevalence of preterm birth is rising, and there are growing concerns about the adverse consequences. This study explored the association between intimate partner violence (IPV) during pregnancy and preterm birth in Zimbabwe.

Methods

Using data from the 2015 Zimbabwe Demographic and Health Survey, we applied propensity score matching to estimate the effect of IPV during pregnancy on preterm birth among women of reproductive age (15–49 years). A total of 4833 pregnant women who gave birth during the five years preceding the survey were analysed.

Results

We successfully matched 79 women who were exposed to IPV during pregnancy to 372 unexposed during pregnancy. Using the matched sample, the probability of preterm delivery was significantly higher among women who were exposed to IPV during pregnancy than those who were not exposed. The findings showed that 7 out of 79 (8.9%) of women exposed to IPV during pregnancy experienced preterm delivery, and 11 out of 372 (3.0%) of those who were not exposed to IPV during pregnancy experienced preterm delivery. In the urban areas, those exposed to IPV during pregnancy were almost five times more likely to experience preterm delivery (OR = 4.8, 95% CI 2.0–11.6), but the association was not significantly different among women in rural areas.

Conclusion

The findings showed that women exposed to IPV during pregnancy were at increased risk of preterm birth. Some of the risk factors associated with IPV were urban residence, low economic status and unemployment. Effective policies and programmes are required to address the issue of IPV in Zimbabwe.

Uteroplacental nutrient flux and evidence for metabolic reprogramming during sustained hypoxemia

Gestational hypoxemia is often associated with reduced birth weight, yet how hypoxemia controls uteroplacental nutrient metabolism and supply to the fetus is unclear. This study tested the effects of maternal hypoxemia (HOX) between 0.8 and 0.9 gestation on uteroplacental nutrient metabolism and flux to the fetus in pregnant sheep. Despite hypoxemia, uteroplacental and fetal oxygen utilization and net glucose and lactate uptake rates were similar in HOX (n = 11) compared to CON (n = 7) groups. HOX fetuses had increased lactate and pyruvate concentrations and increased net pyruvate output to the utero-placenta. In the HOX group, uteroplacental flux of alanine to the fetus was decreased, as was glutamate flux from the fetus. HOX fetuses had increased alanine and decreased aspartate, serine, and glutamate concentrations. In HOX placental tissue, we identified hypoxic responses that should increase mitochondrial efficiency (decreased SDHB, increased COX4I2) and increase lactate production from pyruvate (increased LDHA protein and LDH activity, decreased LDHB and MPC2), both resembling metabolic reprogramming, but with evidence for decreased (PFK1, PKM2), rather than increased, glycolysis and AMPK phosphorylation. This supports a fetal-uteroplacental shuttle during sustained hypoxemia whereby uteroplacental tissues produce lactate as fuel for the fetus using pyruvate released from the fetus, rather than pyruvate produced from glucose in the placenta, given the absence of increased uteroplacental glucose uptake and glycolytic gene activation. Together, these results provide new mechanisms for how hypoxemia, independent of AMPK activation, regulates uteroplacental metabolism and nutrient allocation to the fetus, which allow the fetus to defend its oxidative metabolism and growth.

An observational claims data analysis on the risk of maternal chronic kidney disease after preterm delivery and preeclampsia

Women with complications of pregnancy such as preeclampsia and preterm birth are at risk for adverse long-term outcomes, including an increased future risk of chronic kidney disease (CKD) and end-stage kidney disease (ESKD). This observational cohort study aimed to examine the risk of CKD after preterm delivery and preeclampsia in a large obstetric cohort in Germany, taking into account preexisting comorbidities, potential confounders, and the severity of CKD. Statutory claims data of the AOK Baden-Wuerttemberg were used to identify women with singleton live births between 2010 and 2017. Women with preexisting conditions including CKD, ESKD, and kidney replacement therapy (KRT) were excluded. Preterm delivery (< 37 gestational weeks) was the main exposure of interest; preeclampsia was investigated as secondary exposure. The main outcome was a newly recorded diagnosis of CKD in the claims database. Data were analyzed using Cox proportional hazard regression models. The time-dependent occurrence of CKD was analyzed for four strata, i.e., births with (i) neither an exposure of preterm delivery nor an exposure of preeclampsia, (ii) no exposure of preterm delivery but exposure of at least one preeclampsia, (iii) an exposure of at least one preterm delivery but no exposure of preeclampsia, or (iv) joint exposure of preterm delivery and preeclampsia. Risk stratification also included different CKD stages. Adjustments were made for confounding factors, such as maternal age, diabetes, obesity, and dyslipidemia. The cohort consisted of 193,152 women with 257,481 singleton live births. Mean observation time was 5.44 years. In total, there were 16,948 preterm deliveries (6.58%) and 14,448 births with at least one prior diagnosis of preeclampsia (5.61%). With a mean age of 30.51 years, 1,821 women developed any form of CKD. Compared to women with no risk exposure, women with a history of at least one preterm delivery (HR = 1.789) and women with a history of at least one preeclampsia (HR = 1.784) had an increased risk for any subsequent CKD. The highest risk for CKD was found for women with a joint exposure of preterm delivery and preeclampsia (HR = 5.227). These effects were the same in magnitude only for the outcome of mild to moderate CKD, but strongly increased for the outcome of severe CKD (HR = 11.90). Preterm delivery and preeclampsia were identified as independent risk factors for all CKD stages. A joint exposure or preterm birth and preeclampsia was associated with an excessive maternal risk burden for CKD in the first decade after pregnancy. Since consequent follow-up policies have not been defined yet, these results will help guide long-term surveillance for early detection and prevention of kidney disease, especially for women affected by both conditions.

Maternal HIV Infection and Spontaneous Versus Provider-Initiated Preterm Birth in an Urban Zambian Cohort

OBJECTIVE

We investigated the effect of maternal HIV and its treatment on spontaneous and provider-initiated preterm birth (PTB) in an urban African cohort.

METHODS

The Zambian Preterm Birth Prevention Study enrolled pregnant women at their first antenatal visit in Lusaka. Participants underwent ultrasound, laboratory testing, and clinical phenotyping of delivery outcomes. Key exposures were maternal HIV serostatus and timing of antiretroviral therapy initiation. We defined the primary outcome, PTB, as delivery between 16 and 37 weeks' gestational age, and differentiated spontaneous from provider-initiated parturition.

RESULTS

Of 1450 pregnant women enrolled, 350 (24%) had HIV. About 1216 (84%) were retained at delivery, 3 of whom delivered <16 weeks. Of 181 (15%) preterm deliveries, 120 (66%) were spontaneous, 56 (31%) were provider-initiated, and 5 (3%) were unclassified. In standardized analyses using inverse probability weighting, maternal HIV increased the risk of spontaneous PTB [RR 1.68; 95% confidence interval (CI): 1.12 to 2.52], but this effect was mitigated on overall PTB [risk ratio (RR) 1.31; 95% CI: 0.92 to 1.86] owing to a protective effect against provider-initiated PTB. HIV reduced the risk of preeclampsia (RR 0.32; 95% CI: 0.11 to 0.91), which strongly predicted provider-initiated PTB (RR 17.92; 95% CI: 8.13 to 39.53). The timing of antiretroviral therapy start did not affect the relationship between HIV and PTB.

CONCLUSION

The risk of HIV on spontaneous PTB seems to be opposed by a protective effect of HIV on provider-initiated PTB. These findings support an inflammatory mechanism underlying HIV-related PTB and suggest that published estimates of PTB risk overall underestimate the risk of spontaneous PTB.

Teenage pregnancy as a risk factor for placental abruption: Findings from the prospective Japan environment and children's study

Objective

Placental abruption is a significant obstetric complication that affects both maternal and neonatal mortality and morbidity. The present study examined the effect of maternal age on the incidence of placental abruption.

Methods

We used data of singleton pregnancies from the Japan Environment and Children’s Study, which was a prospective birth cohort study conducted between January 2011 and March 2014 across 15 regional centers in Japan. A multiple regression model was used to identify whether maternal age (<20 years, 20–24 years, 25–29 years, 30–34 years, and ≥35 years) is a risk factor for placental abruption. The analyses were conducted while considering the history of placental abruption, assisted reproductive technology, number of previous deliveries, smoking during pregnancy, body mass index before pregnancy, and chronic hypertension.

Results

A total of 94,410 Japanese women (93,994 without placental abruption and 416 with placental abruption) were recruited. Herein, 764, 8421, 25915, 33517, and 25793 women were aged <20 years, 20–24 years, 25–29 years, 30–34 years, and ≥35 years, respectively. Besides advanced maternal age (≥35 years; adjusted odds ratio: 1.7, 95% confidence interval: 1.1–2.5), teenage pregnancy was also a risk factor for placental abruption (adjusted odds ratio: 2.8, 95% confidence interval: 1.2–6.5) when the maternal age of 20–24 years was set as a reference.

Conclusions

In the Japanese general population, besides advanced maternal age, teenage pregnancy was associated with placental abruption. Recently, the mean maternal age has been changing in Japan. Therefore, it is important for obstetric care providers to provide proper counseling to young women based on up-to-date evidence.

Vaginal Microbiome Composition in Early Pregnancy and Risk of Spontaneous Preterm and Early Term Birth Among African American Women

Objective

To evaluate the association between the early pregnancy vaginal microbiome and spontaneous preterm birth (sPTB) and early term birth (sETB) among African American women.

Methods

Vaginal samples collected in early pregnancy (8-14 weeks' gestation) from 436 women enrolled in the Emory University African American Vaginal, Oral, and Gut Microbiome in Pregnancy Study underwent 16S rRNA gene sequencing of the V3-V4 region, taxonomic classification, and community state type (CST) assignment. We compared vaginal CST and abundance of taxa for women whose pregnancy ended in sPTB (N = 44) or sETB (N= 84) to those who delivered full term (N = 231).

Results

Nearly half of the women had a vaginal microbiome classified as CST IV (Diverse CST), while one-third had CST III (L. iners dominated) and just 16% had CST I, II, or V (non-iners Lactobacillus dominated). Compared to vaginal CST I, II, or V (non-iners Lactobacillus dominated), both CST III (L. iners dominated) and CST IV (Diverse) were associated with sPTB with an adjusted odds ratio (95% confidence interval) of 4.1 (1.1, infinity) and 7.7 (2.2, infinity), respectively, in multivariate logistic regression. In contrast, no vaginal CST was associated with sETB. The linear decomposition model (LDM) based on amplicon sequence variant (ASV) relative abundance found a significant overall effect of the vaginal microbiome on sPTB (p=0.034) but not sETB (p=0.320), whereas the LDM based on presence/absence of ASV found no overall effect on sPTB (p=0.328) but a significant effect on sETB (p=0.030). In testing for ASV-specific effects, the LDM found that no ASV was significantly associated with sPTB considering either relative abundance or presence/absence data after controlling for multiple comparisons (FDR 10%), although in marginal analysis the relative abundance of Gardnerella vaginalis (p=0.011), non-iners Lactobacillus (p=0.016), and Mobiluncus curtisii (p=0.035) and the presence of Atopobium vaginae (p=0.049), BVAB2 (p=0.024), Dialister microaerophilis (p=0.011), and Prevotella amnii (p=0.044) were associated with sPTB. The LDM identified the higher abundance of 7 ASVs and the presence of 13 ASVs, all commonly residents of the gut, as associated with sETB at FDR < 10%.

Conclusions

In this cohort of African American women, an early pregnancy vaginal CST III or IV was associated with an increased risk of sPTB but not sETB. The relative abundance and presence of distinct taxa within the early pregnancy vaginal microbiome was associated with either sPTB or sETB.

Recurrence rate of preterm birth and associated factors among women who delivered at Kilimanjaro Christian Medical Centre in Northern Tanzania: A registry based cohort study

BACKGROUND

Preterm birth is a public health problem particularly in low- and middle-income countries especially in sub-Saharan Africa. It is associated with infant morbidity and mortality. Survivor of preterm suffers long term health consequences such as respiratory, hearing and visual problems as well as delivering preterm infants. Preterm birth also tends to recur in subsequent pregnancies. Little is known about recurrent rate of preterm birth and associated factors in Tanzania. This study aimed to determine the recurrence rate of preterm birth and associated factors among women who delivered at Kilimanjaro Christian Medical Centre (KCMC), in Northern Tanzania.

METHODS

A historic cohort study was designed using maternally-linked data from KCMC medical birth registry. Women who delivered 2 or more singletons were included. A total of 5,946 deliveries were analysed. Recurrence of preterm birth and associated risk factors were estimated using multivariable log-binomial regression model with robust standard error to account for repeated births from the same mother.

RESULTS

Overall recurrent rate of preterm birth was 24.4%. The recurrence of early preterm birth was higher compared to late preterm birth (26.2% vs. 24.2%). Similar pattern of recurrence was observed for spontaneous and medically indicated preterm birth (13.5% vs. 10.9%, respectively). Previous preterm birth (RR;1.85, 95% CI: 1.49, 2.31), preeclampsia (RR;1.46, 95% CI: 1.07, 2.00), long inter-pregnancy interval (RR;1.22, 95% CI: 1.01, 1.49) and clinical subtypes (RR = 1.37, 95% CI: 1.00, 1.86) were important predictors for recurrent preterm birth.

CONCLUSION

Recurrence of preterm birth remains higher in this population. The rate of preterm recurrence was dependent of gestational age and sub-clinical subtype. Other factors which were associated with recurrence of preterm birth were previous preterm birth, preeclampsia and long inter-pregnancy interval. Early identification of high risk women during prenatal period is warranted.

Combining early (<11 weeks' gestation) ultrasound features and maternal factors to predict small-for-gestational age neonates

Objectives

Placental related adverse pregnancy outcomes such as fetal growth restriction have significant short- and long-term implications for both mother and fetus. This study aimed to determine if conventional and novel early first trimester ultrasound measures are associated with small for gestational age (SGA) neonates. In addition, we aimed to assess whether a combination of ultrasound measures, maternal characteristics and biochemistry improved the prediction of this adverse pregnancy outcome.

Methods

This was a prospective cohort study including ultrasound measurements: trophoblast thickness (TT), trophoblast volume (TV), mean uterine artery pulsatility index, crown-rump length, fetal heart rate, mean sac diameter (MSD) and yolk sac diameter. Biochemical markers considered in the analysis were placental growth factor (PIGF), pregnancy - associated plasma protein A (PAPP-A), beta human chorionic gonadotropin and alpha fetoprotein. Regression models were fitted for ultrasound parameters using multiples of the median (MoM). All measures were compared with normal birthweight (BW) ≥10^th centile and SGA (BW < 10^th centile). Logistic regression analysis was used to create a clinical prediction model for SGA based on maternal characteristics, ultrasound measurements at <11 weeks gestational age and maternal biochemistry collected at 10-14 weeks.

Results

As compared to pregnancies delivered of babies with normal BW (n = 1068), MoM values for TT, TV, MSD, PAPP-A and PIGF were significantly reduced (P < 0.05) in pregnancies delivered of SGA babies (n = 73). The proposed logistic regression model includes maternal height, TV and PIGF resulting in an area under the receiver operator curve 0.70 (95% CI 0.63-0.76) for the prediction of SGA.

Conclusion

A significantly decreased TV, measured <11 weeks gestation, is predictive of BW < 10^th centile. With addition of maternal height and PIGF, this three-marker algorithm provided a reasonable predictive value for the development of SGA later in pregnancy.

Association between antenatal care visit and preterm birth: a cohort study in rural Bangladesh

BACKGROUND

Strengthening the antenatal care programme is suggested as one of the public health strategies to reduce preterm birth burden at a population level. However, the evidence so far available is inconclusive.

OBJECTIVES

To evaluate the association between antenatal care (ANC) visit and preterm birth; and also to explore to what extent the increased usage of ANC after the initiation of the Maternal, Neonatal and Child Health (MNCH) project in Matlab, Bangladesh, contributed to the reduction of preterm birth.

SETTING

This population-based cohort study was conducted in Matlab, a subdistrict under Chandpur. The analysis was based on data collected from 2005 to 2009. In 2007, an MNCH project was initiated in the area that strengthened the ongoing ANC services.

PARTICIPANTS

In total, 12 980 live births with their mothers during the study period were included in the analysis.

ANALYSIS

We performed logistic regression with generalised estimating equation models to evaluate the associations.

OUTCOME MEASURES

Preterm birth.

RESULTS

The number of ANC visits was associated with preterm birth in a dose-dependent way (p for linear trend <0.001). The adjusted odds of preterm birth were 2.4-times higher (OR 2.37, 95% CI 2.07 to 2.70) among women who received ≤1 ANC compared with women who received ≥3 ANC. We observed a significant reduction of preterm birth rates (OR 0.69, 95% CI 0.61 to 0.77) in the period after (2008 to 2009) MNCH project initiation in comparison to the period before (2005 to 2006). Controlling for ANC visits substantially attenuated this observed effect of the MNCH project on preterm birth (OR 0.88, 95% CI 0.77 to 0.99) (Sobel test of mediation p<0.001).

CONCLUSIONS

ANC visits are associated with decreased occurrences of preterm births. Strengthening the ANC services should be prioritised in countries with high preterm birth rates to reduce the preterm birth burden at the population level.

Cortical Gray Matter Injury in Encephalopathy of Prematurity: Link to Neurodevelopmental Disorders

Preterm-born infants frequently suffer from an array of neurological damage, collectively termed encephalopathy of prematurity (EoP). They also have an increased risk of presenting with a neurodevelopmental disorder (e.g., autism spectrum disorder; attention deficit hyperactivity disorder) later in life. It is hypothesized that it is the gray matter injury to the cortex, in addition to white matter injury, in EoP that is responsible for the altered behavior and cognition in these individuals. However, although it is established that gray matter injury occurs in infants following preterm birth, the exact nature of these changes is not fully elucidated. Here we will review the current state of knowledge in this field, amalgamating data from both clinical and preclinical studies. This will be placed in the context of normal processes of developmental biology and the known pathophysiology of neurodevelopmental disorders. Novel diagnostic and therapeutic tactics required integration of this information so that in the future we can combine mechanism-based approaches with patient stratification to ensure the most efficacious and cost-effective clinical practice.

Ultrasound features prior to 11 weeks' gestation and first-trimester maternal factors in prediction of hypertensive disorders of pregnancy

OBJECTIVES

Maternal hypertensive disorders (MHD), including pregnancy-induced hypertension and pre-eclampsia, are estimated to occur in 7-10% of pregnancies worldwide and have significant short- and long-term implications for both mother and fetus. This study aimed to determine the association of conventional and novel early first-trimester ultrasound measures with MHD and whether these ultrasound measures, combined with maternal characteristics and biochemistry, improve the prediction of MHD.

METHODS

This was a prospective cohort study of consecutive women with a singleton pregnancy, attending for an early (5 + 1 to 11 + 0 weeks' gestation) ultrasound examination at a private obstetric ultrasound practice between February 2016 and August 2018. Recorded ultrasound measurements included mean sac diameter, yolk sac diameter, crown-rump length, fetal heart rate (FHR), trophoblast thickness, trophoblast volume (TV) and mean uterine artery pulsatility index. Maternal biochemistry was assessed at 10-14 weeks and included beta-human chorionic gonadotropin, pregnancy-associated plasma protein-A (PAPP-A), placental growth factor (PlGF) and maternal serum alpha-fetoprotein. Regression models were fitted for each ultrasound parameter and multiples of the median (MoM) were calculated. All measures were compared between women who had a normotensive outcome and those who subsequently developed MHD. Logistic regression analysis was used to create a prediction model for MHD based on maternal characteristics, ultrasound measurements at 5 + 1 to 11 + 0 weeks' gestation and maternal biochemistry at 10-14 weeks.

RESULTS

In total, 1141 women were included in the analysis, of whom 1086 (95.2%) were normotensive at delivery and 55 (4.8%) developed MHD. Women who developed MHD weighed significantly more than did normotensive women (P < 0.0001). Mean MoM values for TV (P = 0.006), PAPP-A (P = 0.031) and PlGF (P = 0.044) were decreased significantly in pregnancies that subsequently developed MHD. The proposed logistic regression model includes maternal weight and height and MoM values for TV, FHR and PlGF, resulting in an area under the receiver-operating-characteristics curve of 0.80 (95% CI, 0.75-0.86).

CONCLUSION

The combination of maternal weight and height, TV and FHR, measured prior to 11 weeks' gestation, and first-trimester PlGF appears to have good predictive value for development of MHD later in pregnancy. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Pregnancy complications and risk of preterm birth according to maternal age: A population-based study of delivery hospitalizations in Alberta

INTRODUCTION

Pregnancy-related medical complications are associated with a 2- to 5-fold increased risk of preterm birth (PTB), but the nature of this etiologic relation in context with maternal factors remains poorly understood. Previous studies have generally treated maternal age as a confounder but overlooked its potential as an effect modifier, whereby the magnitude of the effect of complications on PTB could differ significantly across age groups. We investigated whether advanced maternal age (≥35 years) modified the association between pregnancy complications and PTB, and compared population-attributable fractions of PTB from complications in women older vs younger than 35 years.

MATERIAL AND METHODS

We analyzed population-based, cross-sectional data from the Alberta Discharge Abstract Database for women aged 18-50 years with singleton live births in hospital between 2014 and 2017 (n = 152 246). Complications were preeclampsia, gestational diabetes, and placental disorders identified using diagnostic codes. Outcomes were spontaneous (sPTB) or iatrogenic (iPTB) PTB before 37 weeks of gestation. We estimated risk ratios and risk differences using modified Poisson and log binomial regression, respectively, adjusting for confounders (pregnancy history, comorbidities). Population-attributable fractions estimates were calculated from risk ratios. Age modification was tested using interaction terms and Z-tests.

RESULTS

Prevalence of advanced maternal age was 19.2%. Pregnancy complications and s/iPTB were more common among women aged ≥35 years. Age modified the risk of PTB from preeclampsia only, with risk differences of 9.9% (95% CI 7.2%-12.6%) in older women vs 6.1% (95% CI 4.8%-7.4%) in younger women (P-interaction = 0.012) for sPTB, and 29.5% (95% CI 26.0%-33.1%) vs 20.8% (95% CI 18.9%-22.6%, P-interaction <0.001) for iPTB. Population-attributable fractions of s/iPTB types for all complications were consistently 2%-5% larger in women aged ≥35 years, and significantly larger for preeclampsia (sPTB: 5.1% vs 2.7%, P = 0.002; iPTB: 18.8% vs 14.0%, P < 0.001) and placental disorders (sPTB: 12.5% vs 8.7%, P < 0.001; iPTB: 13.2% vs 8.9%, P < 0.001).

CONCLUSIONS

Of the pregnancy complications studied, advanced maternal age only modified the association between PTB and preeclampsia, such that older women with preeclampsia have a higher risk for s/iPTB than younger counterparts. Pregnancy complications contribute to a sizable proportion of PTBs in Alberta, especially among women aged ≥35 years. Findings may inform clinical risk assessment and population-level policy targeting PTB.

A Complicated Pregnancy in an Adult with HNF4A p.R63W-Associated Fanconi Syndrome

Renal Fanconi syndrome (RFS) is characterised by generalised dysfunction of the proximal renal tubules, resulting in excessive urinary loss of solutes, most notably bicarbonate, and type II (proximal) renal tubular acidosis. It is a rare condition, and literature around its management through pregnancy is limited. We present the management of a 37-year-old woman with RFS secondary to the HNF4A p.R63W mutation, through her third pregnancy. She presented at 28 + 5 weeks with dehydration, low serum bicarbonate, and profound metabolic acidosis. Daily infusions of sodium bicarbonate were necessary, and the requirements increased throughout the pregnancy. She also demonstrated both fasting hypoglycaemia and episodes of postprandial hyperglycaemia which required complex management. Due to concerns around fetal health, an elective caesarean section was performed at 34 weeks, delivering a healthy baby girl. This case highlights the potential complexity of pregnancy in patients with RFS and the need for a multidisciplinary approach to its management.

Changes in the Prevalence of Chronic Hypertension in Pregnancy, United States, 1970 to 2010

We estimated changes in the prevalence of chronic hypertension among pregnant women and evaluated the extent to which changes in obesity and smoking were associated with these trends. We designed a population-based cross-sectional analysis of over 151 million women with delivery-related hospitalizations in the United States, 1970 to 2010. Maternal age, year of delivery (period), and maternal year of birth (birth cohort), as well as race, were examined as risk factors for chronic hypertension. Prevalence rates and rate ratios with 95% CIs of chronic hypertension in relation to age, period, and birth cohort were derived through age-period-cohort models. We also examined how changes in obesity and smoking rates influenced age-period-cohort effects. The overall prevalence of chronic hypertension was 0.63%, with black women (1.24%) having more than a 2-fold higher rate than white women (0.53%; rate ratio, 2.31; 95% CI, 2.30–2.32). In the age-period-cohort analysis, the rate of chronic hypertension increased sharply with advancing age and period from 0.11% in 1970 to 1.52% in 2010 (rate ratio, 13.41; 95% CI, 13.22–13.61). The rate of hypertension increased, on average, by 6% (95% CI, 5–6) per year, with the increase being slightly higher among white (7%; 95% CI, 6%–7%) than black (4%; 95% CI, 3%–4%) women. Adjustments for changes in rates of obesity and smoking were not associated with age and period effects. We observed a substantial increase in chronic hypertension rates by age and period and an over 2-fold race disparity in chronic hypertension rates.

PREPARE: protocol for a stepped wedge trial to evaluate whether a risk stratification model can reduce preterm deliveries among women with suspected or confirmed preterm pre-eclampsia

BACKGROUND

Preeclampsia (PE) is a major cause of short and long-term morbidity for affected infants, including consequences of fetal growth restriction and iatrogenic prematurity. In Brazil, this is a special problem as PE accounts for 18% of preterm births (PTB). In the PREPARE (Prematurity REduction by Pre-eclampsia cARE) study, we will test a novel system of integrated care based on risk stratification and knowledge transfer, to safely reduce PTB.

METHODS

This is a stepped wedge cluster randomised trial that will include women with suspected or confirmed PE between 20 + 0 and 36 + 6 gestational weeks. All pregnant women presenting with these findings at seven tertiary centres in geographically dispersed sites, throughout Brazil, will be considered eligible and evaluated in terms of risk stratification at admission. At randomly allocated time points, sites will transition to risk stratification performed according to sFlt-1/PlGF (Roche Diagnostics) measurement and fullPIERS score with both results will be revealed to care providers. The healthcare providers of women stratified as low risk for adverse outcomes (sFlt-1/PlGF ≤38 AND fullPIERS< 10% risk) will receive the recommendation to defer delivery. sFlt-1/PlGF will be repeated once and fullPIERS score twice a week. Rates of prematurity due to preeclampsia before and after the intervention will be compared. Additionally, providers will receive an active program of knowledge transfer about WHO recommendations for preeclampsia, including recommendations regarding antenatal corticosteroids for foetal benefits, antihypertensive therapy and magnesium sulphate for seizure prophylaxis. This study will have 90% power to detect a reduction in PTB associated with PE from a population estimate of 1.5 to 1.0%, representing a 33% risk reduction, and 80% power to detect a reduction from 2.0 to 1.5% (25% risk reduction). The necessary number of patients recruited to achieve these results is 750. Adverse events, serious adverse events, both anticipated and unanticipated will be recorded.

DISCUSSION

The PREPARE intervention expects to reduce PTB and improve care of women with PE without significant adverse side effects. If successful, this novel pathway of care is designed for rapid translation to healthcare throughout Brazil and may be transferrable to other low and middle income countries.

TRIAL REGISTRATION

ClinicalTrials.gov : NCT03073317.

Cerebrovascular disease after placental abruption: A population-based prospective cohort study

OBJECTIVE

To test whether abruption during pregnancy is associated with long-term cerebrovascular disease by assessing the incidence and mortality from stroke among women with abruption.

METHODS

We designed a population-based prospective cohort study of women who delivered in Denmark from 1978 to 2010. We used data from the National Patient Registry, Causes of Death Registry, and Danish Birth Registry to identify women with abruption, cerebrovascular events, and deaths. The outcomes included deaths resulting from stroke and nonfatal ischemic and hemorrhagic strokes. We fit Cox proportional hazards regression models for stroke outcomes, adjusting for the delivery year, parity, education, and smoking.

RESULTS

The median (interquartile range) follow-up in the nonabruption and abruption groups was 15.9 (7.8-23.8) and 16.2 (9.6-23.1) years, respectively, among 828,289 women with 13,231,559 person-years of follow-up. Cerebrovascular mortality rates were 0.8 and 0.5 per 10,000 person-years among women with and without abruption, respectively (hazard ratio [HR] 1.6, 95% confidence interval [CI] 0.9-3.0). Abruption was associated with increased rates of nonfatal ischemic stroke (HR 1.4, 95% CI 1.1-1.7) and hemorrhagic stroke (HR 1.4, 95% CI 1.1-1.9). The association of abruption and stroke was increased with delivery at <34 weeks, when accompanied by ischemic placental disease, and among women with ≥2 abruptions. These associations are less likely to have been affected by unmeasured confounding.

CONCLUSION

Abruption is associated with increased risk of cerebrovascular morbidity and mortality. Disruption of the hemostatic system manifesting as ischemia and hemorrhage may indicate shared etiologies between abruption and cerebrovascular complications.

Uterine Artery Pulsatility Index Assessment at <11 Weeks' Gestation: A Prospective Study

OBJECTIVE

Mean uterine artery pulsatility index (meanUAPI) is commonly measured at 11-13+6 weeks to predict adverse pregnancy outcomes including hypertensive disorders and small-for-gestational age. The aims of this study were to establish a population-specific reference range for meanUAPI at <11 weeks, to determine if an abnormal meanUAPI at <11 weeks was associated with adverse pregnancy outcome, and to assess changes in meanUAPI between <11 weeks and 11-13+6 weeks.

METHODS

A prospective cohort was examined at <11 weeks and at 11-13+6 weeks to develop reference ranges for meanUAPI. Based on these regression models, meanUAPI Z-scores were compared between outcome groups using a two-sample t test. Longitudinal changes in the meanUAPI between <11 and 11-13+6 weeks were assessed by two-way mixed ANOVA.

RESULTS

Prior to 11 weeks, there was no significant difference in meanUAPI between normal (n = 622) and adverse (n = 80) outcomes (mean [95% CI]: 2.62 [2.57-2.67] and 2.67 [2.50-2.84], respectively; p = 0.807). At 11-13+6 weeks, meanUAPI was significantly higher in the adverse (n = 66) compared with the normal (n = 535) outcome group (mean [95% CI]: 1.87 [1.70-2.03] and 1.67 [1.63-1.72], respectively; p = 0.040). There was a statistically significant decrease (p < 0.0001) in meanUAPI between the two time points.

CONCLUSION

MeanUAPI measured at <11 weeks' gestation does not appear to be a useful marker for the prediction of placental-related adverse pregnancy outcomes, supporting an argument for the prediction of risk at 11-13+6 weeks' gestation.

Management of subglottic stenosis in pregnancy using advanced apnoeic ventilatory techniques

Objective

To describe the use of balloon dilation with non-invasive ventilation in the treatment of pregnant patients with idiopathic subglottic stenosis.

Methods

The medical charts of four consecutive patients who underwent jet ventilation or high-flow nasal cannula oxygenation with balloon dilation for the treatment of idiopathic subglottic stenosis during pregnancy were reviewed.

Results

Objective improvement of subglottic stenosis was seen in all four cases, with end-result Myer–Cotton grade 1 lesions down from pre-procedure grade 3 lesions. Patients also reported subjective improvements in symptomatology, with no further airway issues. All patients delivered normally, at term.

Conclusion

Laryngeal dilation with continuous radial expansion pulmonary balloons using non-invasive ventilation for the treatment of idiopathic subglottic stenosis in pregnant patients is safe and efficacious, and should be the first line treatment option for this patient population. The improvement in symptoms, and lack of labour and pregnancy complications, distinguish this method of treatment from others reported in the literature.

Exposures to Air Pollution and Risk of Acute-onset Placental Abruption: A Case-crossover Study

BACKGROUND

Despite abruption's elusive etiology, knowledge of triggers that precede it by just a few days prior to delivery may help to understand the underpinnings of this acute obstetrical complication. We examine whether air pollution exposures immediately preceding delivery are associated with acute-onset abruptions.

METHODS

We applied a bidirectional, time-stratified, case-crossover design to births with an abruption diagnosis in New York City, 2008-2014. We measured ambient fine particulate matter (PM2.5) and nitrogen dioxide (NO2). We fit distributed lag nonlinear models based on conditional logistic regression to evaluate individual exposure and cumulative exposures over lags 0-7 days before abruption, adjusted for temperature and relative humidity (similar lags to the main exposures).

RESULTS

We identified 1,190 abruption cases. We observed increased odds of abruption for exposure to PM2.5 (per 10 μg/m) on lag day 3 (odds ratio [OR] 1.19, 95% confidence interval [CI] = 0.98, 1.43), lag day 4 (OR 1.21, 95% CI = 1.01, 1.46), and lag day 5 (OR 1.17, 95% CI = 1.03, 1.33). Similarly, the odds of abruption increased with exposure to NO2 (per 5 ppb) on lag day 3 (OR 1.16, 95% CI = 0.98, 1.37), lag day 4 (OR 1.19, 95% CI = 1.02, 1.39), and lag day 5 (OR 1.16, 95% CI = 1.05, 1.27). Exposures to PM2.5 and NO2 at other lags, or cumulative exposures, were not associated with abruption of acute onset.

CONCLUSIONS

This case-crossover study showed evidence of an association between short-term ambient air pollution exposures and increased abruption risk of acute onset.

Risk Factors for Very Preterm Births in French Guiana: The Burden of Induced Preterm Birth

Background  Early preterm births are still represented as a major public health problem in French Guiana. The objective of the present study was to study factors associated with early preterm birth in French Guiana. Methods  A monocentric age-matched case control study was conducted at the sole level 3 maternity in French Guiana. In utero fetal deaths and multiple pregnancies were not included. Cases were defined as giving birth prematurely between 22 and 32 weeks of pregnancy. Controls were defined as women delivering on term. For each case three controls were matched on age. In utero deaths, medical pregnancy interruptions and multiple pregnancies (a known major cause of preterm delivery) were excluded from the study. Sociodemographic variables, medical and obstetrical history, the complications of the current pregnancy, and the results of the last vaginal swab before delivery were recorded in the second or the third trimester. Thematic conditional logistic regression models were computed. Results  Overall 94 cases and 282 matched controls were included. Preterm delivery was spontaneous in 47.9% (45/94) of the cases and induced in 52.1% (49/94).A history of preterm birth was associated with both spontaneous and induced preterm delivery. The absence of health insurance was associated with spontaneous early preterm delivery AOR (adjusted odd ratio) = 9.1 (2.2-38.3), p  = 0.002 but not induced preterm delivery adjusted odd ratio (AOR) = 2.1 (0.6-6.7), p  = 0.2. Gravidic hypertension, placenta praevia, intrauterine growth retardation and mostly preeclampsia (66%, 32/49) were linked to induced preterm delivery but not spontaneous delivery. Gardnerellavaginalis and group B Streptococcus infections were significantly associated with induced early preterm delivery but not spontaneous early preterm delivery. Conclusions  Social factors were associated with spontaneous early preterm delivery, suggesting that efforts to reduce psychosocial stressors could lead to potential improvements. Vaginal infections were also associated with induced preterm labor suggesting that early diagnosis and treatment could reduce induced early preterm delivery. Preeclampsia was a major contributor to induced early preterm delivery. Reliable routine predictors of preeclampsia are still not available which makes its prevention impossible in first pregnancies.

Neuroprotection of the preterm brain

Despite notable advances in the care and survival of preterm infants, a significant proportion of preterm neonates will have life-long cognitive, behavioral, and motor deficits, and robustly effective neuroprotective strategies are still missing. These therapies must target the pathophysiologic mechanisms observed in contemporaneous infants and rely on modern epidemiology, imaging, and experimental models and assessment techniques. Two drugs, magnesium sulfate and caffeine, are already in use in several units, and although their targets are apnea of prematurity and myometrial contractility (respectively), they do offer improved odds of positive outcomes. Nevertheless, these drugs have limited efficacy, and NICU-to-NICU administration varies greatly. As such, there is an obvious need for additional specific neurotherapeutic strategies to further enhance the outcome of this very fragile population of neonates. The chapter reviews these issues, highlights bottlenecks that need to be solved for meaningful progress in the field, and proposes future innovative avenues for intervention, including delayed interventions.

Association Between Temporal Changes in Neonatal Mortality and Spontaneous and Clinician-Initiated Deliveries in the United States, 2006-2013

IMPORTANCE

Preterm and postterm deliveries have declined since 2005 in the United States, but the association between these changes and neonatal mortality remains unknown.

OBJECTIVE

To estimate changes in the gestational age distribution among spontaneous and clinician-initiated deliveries between 2006 and 2013 and associated changes in neonatal mortality.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort analysis was conducted of 22 million singleton live births without major malformations in the United States from 2006 to 2013. Data analysis was performed from August to October 2017.

MAIN OUTCOMES AND MEASURES

Changes in gestational age distribution among spontaneous and clinician-initiated deliveries at extremely preterm (20-27 weeks), very preterm (28-31 weeks), moderately preterm (32-33 weeks), late preterm (34-36 weeks), early term (37-38 weeks), term (39-40), late term (41 weeks), and postterm (42-44 weeks) gestations and changes in neonatal mortality rates at less than 28 days between 2006 and 2013. These changes were estimated from log-linear Poisson regression models with robust variance, adjusted for confounders.

RESULTS

Among 22 million births, 12 493 531 (56.7%) were spontaneous and 9 557 815 (43.3%) were clinician-initiated deliveries. Among spontaneous deliveries, the proportion of births at 20 to 27, 28 to 31, 32 to 33, 34 to 36, and 37 to 38 weeks declined. Among clinician-initiated deliveries, the proportion of births at 34 to 36 and 37 to 38 weeks declined and the proportion at 39 to 40 weeks increased. Among spontaneous deliveries, overall neonatal mortality rates declined from 1.8 to 1.3 per 1000 live births, mainly at 20 to 27 weeks (adjusted annual decline, 1%; 95% CI, -2% to -1%) and 28 to 31 weeks (adjusted annual decline, 6%; 95% CI, -8% to -5%). Among clinician-initiated deliveries, overall mortality rates remained unchanged (2.1 to 2.2 per 1000 live births). However, mortality rates declined (0.6 to 0.5 per 1000 live births) at 39 to 40 weeks by 1% (95% CI, -3% to -0.4%) annually, adjusted for confounders.

CONCLUSIONS AND RELEVANCE

In the United States, there was a decline in spontaneous deliveries associated with an overall decline in neonatal mortality. Although clinician-initiated deliveries increased at 39 to 40 weeks, neonatal mortality at that gestation declined.

Why Is the U.S. Preterm Birth Rate So Much Higher Than the Rates in Canada, Great Britain, and Western Europe?

The portion of newborns delivered before term is considerably higher in the United States than in other developed countries. We compare the array of risk exposures and protective factors common to women across national settings, using national, regional, and international databases, review articles, and research reports. We find that U.S. women have higher rates of obesity, heart disease, and poor health status than women in other countries. This is in part because more U.S. women are exposed to the stresses of racism and income disparity than women in other national settings, and stress loads are known to disrupt physiological functions. Pregnant women in the United States are not at higher risk for preterm birth because of older maternal age or engagement in high-risk behaviors. However, to a greater extent than in other national settings, they are younger and their pregnancies are unintended. Higher rates of multiple gestation pregnancies, possibly related to assisted reproduction, are also a factor in higher preterm birth rates. Reproductive policies that support intentional childbearing and social welfare policies that reduce the stress of income insecurity can be modeled from those in place in other national settings to address at least some of the elevated U.S. preterm birth rate.

Natural Selection Has Differentiated the Progesterone Receptor among Human Populations

The progesterone receptor (PGR) plays a central role in maintaining pregnancy and is significantly associated with medical conditions such as preterm birth that affects 12.6% of all the births in U.S. PGR has been evolving rapidly since the common ancestor of human and chimpanzee, and we herein investigated evolutionary dynamics of PGR during recent human migration and population differentiation. Our study revealed substantial population differentiation at the PGR locus driven by natural selection, where very recent positive selection in East Asians has substantially decreased its genetic diversity by nearly fixing evolutionarily novel alleles. On the contrary, in European populations, the PGR locus has been promoted to a highly polymorphic state likely due to balancing selection. Integrating transcriptome data across multiple tissue types together with large-scale genome-wide association data for preterm birth, our study demonstrated the consequence of the selection event in East Asians on remodeling PGR expression specifically in the ovary and determined a significant association of early spontaneous preterm birth with the evolutionarily selected variants. To reconstruct its evolutionary trajectory on the human lineage, we observed substantial differentiation between modern and archaic humans at the PGR locus, including fixation of a deleterious missense allele in the Neanderthal genome that was later introgressed in modern human populations. Taken together, our study revealed substantial evolutionary innovation in PGR even during very recent human evolution, and its different forms among human populations likely result in differential susceptibility to progesterone-associated disease conditions including preterm birth.

Medically indicated late preterm delivery and its impact on perinatal morbidity and mortality: a retrospective population-based cohort study

Objective: In the last few decades, attention has been focused on morbidity and mortality associated with late preterm delivery (34-36 + 6/7 weeks), accounting for 60-70% of all preterm births. This study is aimed to determine (1) the prevalence of late preterm deliveries (spontaneous and medically indicated) in our population; and (2) the rate of neonatal morbidity and mortality as well as maternal complications associated with the different phenotypes of late preterm deliveries. Study design: This retrospective population-based cohort study, included 96,176 women who had 257,182 deliveries, occurred between 1988 and 2011, allocated into three groups: term (n = 242,286), spontaneous (n = 10,063), and medically indicated (n = 4833) late preterm deliveries. Results: (1) Medically indicated late preterm deliveries were associated with increased maternal morbidity, as well as neonatal morbidity and mortality, in comparison with other study groups (p < .01 for all comparisons); (2) medically indicated late preterm delivery was an independent risk factor for composite neonatal morbidity (low Apgar score at 5', seizures, asphyxia, acidosis) after adjustment for confounding factors (maternal age and ethnicity and neonatal gender) and stratification according to gestational age at delivery; and (3) the proportion of medically indicated late preterm deliveries affected the neonatal mortality rate. Below 35% of all late preterm deliveries, indicated late preterm birth were associated with a reduction in neonatal mortality; however, above this threshold medically indicated late preterm deliveries were associated with an increased risk for neonatal death. Conclusions: (1) Medically indicated late preterm deliveries were independently associated with adverse composite neonatal outcome; and (2) to benefit in term of neonatal outcome from the tool of medically indicated late preterm birth, their proportion should be kept below 35% of all late preterm deliveries, while exceeding this threshold increases the risk of neonatal mortality.

Primary and Repeat Cesarean Deliveries: A Population-based Study in the United States, 1979-2010

BACKGROUND

Despite the temporal increase in cesarean deliveries, the extent to which maternal age, period, and maternal birth cohorts may have contributed to these trends remains unknown.

METHODS

We performed an analysis of 123 million singleton deliveries in the United States (1979-2010). We estimated rate ratio (RR) with 95% confidence interval (CI) for primary and repeat cesarean deliveries. We examined changes in cesarean rates with weighted Poisson regression models across three time-scales: maternal age, year of delivery, and birth cohort (mother's birth year).

RESULTS

The primary cesarean rate increased by 68% (95% confidence interval [CI]: 67%, 69%) between 1979 (11.0%) and 2010 (18.5%). Repeat cesarean deliveries increased by 178% (95% CI: 176, 179) from 5.2% in 1979 to 14.4% in 2010. Cesarean rates increased with advancing age. Compared with 1979, the RR for the period effect in primary and repeat cesarean deliveries increased up to 1990, fell to a nadir at 1993, and began to rise thereafter. A small birth cohort effect was evident, with women born before 1950 at increased risk of primary cesarean; no cohort effect was seen for repeat cesarean deliveries. Adjustment for maternal BMI had a small effect on these findings. Period effects in primary cesarean were explained by a combination of trends in obesity and chronic hypertension, as well as demographic shifts over time.

CONCLUSIONS

Maternal age and period appear to have important contributions to the temporal increase in the cesarean rates, although the effect of parity on these associations remains undetermined.

Placental Complications Associated With Psychostimulant Use in Pregnancy

OBJECTIVE

To evaluate whether psychostimulants used to treat attention-deficit/hyperactivity disorder (ADHD) are associated with risk of adverse placental-associated pregnancy outcomes including preeclampsia, placental abruption, growth restriction, and preterm birth.

METHODS

We designed a population-based cohort study in which we examined a cohort of pregnant women and their liveborn neonates enrolled in Medicaid from 2000 to 2010. Women who received amphetamine-dextroamphetamine or methylphenidate monotherapy in the first half of pregnancy were compared with unexposed women. We considered atomoxetine, a nonstimulant ADHD medication, as a negative control exposure. To assess whether the risk period extended to the latter half of pregnancy, women who continued stimulant monotherapy after 20 weeks of gestation were compared with those who discontinued. Risk ratios and 95% CIs were estimated with propensity score stratification to control for confounders.

RESULTS

Pregnancies exposed to amphetamine-dextroamphetamine (n=3,331), methylphenidate (n=1,515), and atomoxetine (n=453) monotherapy in early pregnancy were compared with 1,461,493 unexposed pregnancies. Among unexposed women, the risks of the outcomes were 3.7% for preeclampsia, 1.4% for placental abruption, 2.9% for small for gestational age, and 11.2% for preterm birth. The adjusted risk ratio for stimulant use was 1.29 for preeclampsia (95% CI 1.11-1.49), 1.13 for placental abruption (0.88-1.44), 0.91 for small for gestational age (0.77-1.07), and 1.06 for preterm birth (0.97-1.16). Compared with discontinuation (n=3,527), the adjusted risk ratio for continuation of stimulant use in the latter half of pregnancy (n=1,319) was 1.26 for preeclampsia (0.94-1.67), 1.08 for placental abruption (0.67-1.74), 1.37 for small for gestational age (0.97-1.93), and 1.30 for preterm birth (1.10-1.55). Atomoxetine was not associated with the outcomes studied.

CONCLUSION

Psychostimulant use during pregnancy was associated with a small increased relative risk of preeclampsia and preterm birth. The absolute increases in risks are small and, thus, women with significant ADHD should not be counseled to suspend their ADHD treatment based on these findings.

Adverse maternal outcomes and birth weight discordance in twin gestation: British Columbia, Canadian data

Objective

The aim of this study was to determine whether twin pregnancies with birth weight discordance were associated with higher rates of maternal morbidities.

Study design

A large retrospective population-based cohort study of twins born in British Columbia, Canada, from 2000 to 2010 was performed. Maternal morbidities and growth discordant were evaluated.

Results

There were 6,328 twin deliveries during the study period. Pregnancies carrying growth-discordant twins had higher frequencies of hypertension disorders, preterm labor, and cesarean delivery compared with growth-concordant twins. They also stayed longer than 3 days in hospital. Multivariate generalized estimating equation modeling found higher odds of preeclampsia, pregnancy-induced hypertension, preterm delivery, and cesarean delivery in mothers carrying growth-discordant twins compared with those carrying growth-concordant category. The modeling also resulted in higher odds in the length of stay longer than 3 days in mothers carrying growth-discordant twins compared with those carrying growth-concordant twins after adjustment for chorionicity.

Conclusion

Maternal complications are associated with growth discordance. Screening for birth weight discordance during pregnancy may alert clinicians to predict subclinical maternal conditions.

Maternal and Neonatal Outcomes in Indicated Preterm Births Based on the Intended Mode of Delivery

OBJECTIVE

To compare maternal and neonatal outcomes in women who underwent induction of labor or planned cesarean delivery in indicated preterm births before 34 weeks of gestation.

METHODS

We conducted a retrospective cohort study of all indicated singleton preterm births (23-34 weeks of gestation) in a tertiary center from 2011 to 2014. The primary maternal outcome was a composite of early postpartum hemorrhage, blood transfusion, operative complications, postpartum complications, and clinical chorioamnionitis. The primary neonatal outcome was a composite of neonatal death, cardiopulmonary resuscitation in the delivery room, grade 3 or 4 intraventricular hemorrhage, necrotizing enterocolitis, culture-proven sepsis, birth trauma, arterial cord gas pH less than 7 or base excess less than -12, and 5-minute Apgar score 3 or less. Outcomes were compared by intended mode of delivery (induction of labor compared with cesarean) and adjusted for confounders. In secondary analyses, maternal and neonatal outcomes based on the intended mode of delivery were stratified by gestational age (23-27 6/7, 28-31 6/7, and 32-33 6/7 weeks of gestation).

RESULTS

Of 629 patients with indicated early preterm births during the study period, 331 (53%) underwent induction of labor, of whom 208 (63%) delivered vaginally. Induction of labor was not associated with an increased risk of the primary maternal (16.3% compared with 19.5%, adjusted odds ratio [OR] 0.8, 95% CI 0.5-1.3) or neonatal composite outcome (14.5% compared with 35.9%, adjusted OR 0.7, 95% CI 0.4-1.1). Analyses stratified by gestational age were consistent with the overall analysis.

CONCLUSION

Maternal and neonatal outcomes do not differ based on the intended mode of delivery. Induction of labor should be considered when early preterm birth is indicated.

Maternal, Labor, Delivery, and Perinatal Outcomes Associated with Placental Abruption: A Systematic Review

Objective Risk factors for placental abruption have changed, but there has not been an updated systematic review investigating outcomes. Methods We searched PubMed, EMBASE, Web of Science, SCOPUS, and CINAHL for publications from January 1, 2005 through December 31, 2016. We reviewed English-language publications reporting estimated incidence and/or risk factors for maternal, labor, delivery, and perinatal outcomes associated with abruption. We excluded case studies, conference abstracts, and studies that lacked a referent/comparison group or did not clearly characterize placental abruption. Results A total of 123 studies were included. Abruption was associated with elevated risk of cesarean delivery, postpartum hemorrhage and transfusion, preterm birth, intrauterine growth restriction or low birth weight, perinatal mortality, and cerebral palsy. Additional maternal outcomes included relaparotomy, hysterectomy, sepsis, amniotic fluid embolism, venous thromboembolism, acute kidney injury, and maternal intensive care unit admission. Additional perinatal outcomes included acidosis, encephalopathy, severe respiratory disorders, necrotizing enterocolitis, acute kidney injury, need for resuscitation, chronic lung disease, infant death, and epilepsy. Conclusion Few studies examined outcomes beyond the initial birth period, but there is evidence that both mother and child are at risk of additional adverse outcomes. There was also considerable variation in, or absence of, the reporting of abruption definitions.