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 Youdens 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..

BACKGROUND: The Eunice Kennedy Shriver National Institute of Child Health and Human Development Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be was established to investigate the underlying causes and pathophysiological pathways associated with adverse pregnancy outcomes in nulliparous gravidas. OBJECTIVE: This study aimed to study placental physiology and identify novel biomarkers concerning adverse pregnancy outcomes, including preterm birth (medically indicated and spontaneous), preeclampsia, small-for-gestational-age neonates, and stillbirth. We measured levels of placental proteins in the maternal circulation in the first 2 trimesters of pregnancy. STUDY DESIGN: Maternal serum samples were collected at 2 study visits (6-13 weeks and 16-21 weeks), and levels of 9 analytes were measured. The analytes we measured were vascular endothelial growth factor, placental growth factor, endoglin, soluble fms-like tyrosine kinase-1, A disintegrin and metalloproteinase domain-containing protein 12, pregnancy-associated plasma protein A, free beta-human chorionic gonadotropin, inhibin A, and alpha-fetoprotein. The primary outcome was preterm birth between 20 0/7 and 36 6/7 weeks of gestation. The secondary outcomes were spontaneous preterm births, medically indicated preterm births, preeclampsia, small-for-gestational-age neonates, and stillbirth. RESULTS: A total of 10,038 eligible gravidas were enrolled in the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be cohort, from which a nested case-control study was performed comparing 800 cases with preterm birth (466 spontaneous preterm births, 330 medically indicated preterm births, and 4 unclassified preterm births), 568 with preeclampsia, 406 with small-for-gestational-age birth, and 49 with stillbirth with 911 controls who delivered at term without complications. Although levels of each analyte generally differed between cases and controls at 1 or 2 visits, the odds ratios revealed a <2-fold difference between cases and controls in all comparisons. Receiver operating characteristic curves, generated to determine the relationship between analyte levels and preterm birth and the other adverse pregnancy outcomes, resulted in areas under the receiver operating characteristic curves that were relatively low (range, 0.50-0.64) for each analyte. Logistic regression modeling demonstrated that areas under the receiver operating characteristic curves for predicting adverse pregnancy outcomes were greater using baseline clinical characteristics and combinations of analytes than baseline characteristics alone, but areas under the receiver operating characteristic curves remained relatively low for each outcome (range, 0.65-0.78). CONCLUSION: We have found significant associations between maternal serum levels of analytes evaluated early in pregnancy and subsequent adverse pregnancy outcomes in nulliparous gravidas. However, the test characteristics for these analytes do not support their use as clinical biomarkers to predict adverse pregnancy outcomes, either alone or in combination with maternal clinical characteristics.

Objective

To examine maternal, psychosocial, and pregnancy factors associated with breastfeeding for at least 6 months in those giving birth for the first time.

Methods

We performed a planned secondary analysis of an observational cohort study of 5249 women giving birth for the first time. Women were contacted at least 6 months after delivery and provided information regarding breastfeeding initiation, duration, and exclusivity. Maternal demographics, psychosocial measures, and delivery methods were compared by breastfeeding groups.

Results

4712 (89.8%) of the women breastfed at some point, with 2739 (58.2%) breastfeeding for at least 6 months. Of those who breastfed, 1161 (24.7% of the entire cohort), breastfed exclusively for at least 6 months. In the multivariable model among those who ever breastfed, not smoking in the month prior to delivery (adjusted odds ratio [aOR] 2.04, 95%CI 1.19-3.45), having a Master's degree of higher (aOR 1.89, 95%CI 1.51-2.36), having a planned pregnancy (aOR 1.48, 95%CI 1.27-1.73), older age (aOR 1.02, 95% CI, 1.01-1.04), lower BMI (aOR 0.96 95% CI 0.95-0.97), and having less anxiety measured during pregnancy (aOR 0.990, 95%CI 0.983-0.998) were associated with breastfeeding for at least 6 months. Compared to non-Hispanic White women, Hispanic women, while being more likely to breastfeed initially (aOR 1.40, 95%CI 1.02-1.92), were less likely to breastfeed for 6 months (aOR 0.72, 95%CI 0.59-0.88). While non-Hispanic Black women were less likely than non-Hispanic White women to initiate breastfeeding (aOR 0.68, 95%CI 0.51-0.90), the odds of non-Hispanic Black women of continuing to breastfeed for at least 6 months was similar to non-Hispanic White women (aOR 0.92, 95%CI 0.71-1.19).

Conclusions

In this cohort of women giving birth for the first time, duration of breastfeeding was associated with several characteristics which highlight groups at greater risk of not breastfeeding as long as currently recommended.

Trial registration

NCT01322529 (nuMoM2b) and NCT02231398 (nuMoM2b-Heart Health).

Objective

The aim of study is to compare the performance of ultrasonographic customized and population fetal growth standards for prediction adverse perinatal outcomes.

Study design

This was a secondary analysis of the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be, in which l data were collected at visits throughout pregnancy and after delivery. Percentiles were assigned to estimated fetal weights (EFWs) measured at 22 to 29 weeks using the Hadlock population standard and a customized standard (www.gestation.net). Areas under the curve were compared for the prediction of composite and severe composite perinatal morbidity using EFW percentile.

Results

Among 8,701 eligible study participants, the population standard diagnosed more fetuses with fetal growth restriction (FGR) than the customized standard (5.5 vs. 3.5%, p < 0.001). Neither standard performed better than chance to predict composite perinatal morbidity. Although the customized performed better than the population standard to predict severe perinatal morbidity (areas under the curve: 0.56 vs. 0.54, p = 0.003), both were poor. Fetuses considered FGR by the population standard but normal by the customized standard had morbidity rates similar to fetuses considered normally grown by both standards.The population standard diagnosed FGR among black women and Hispanic women at nearly double the rate it did among white women (p < 0.001 for both comparisons), even though morbidity was not different across racial/ethnic groups. The customized standard diagnosed FGR at similar rates across groups. Using the population standard, 77% of FGR cases were diagnosed among female fetuses even though morbidity among females was lower (p < 0.001). The customized model diagnosed FGR at similar rates in male and female fetuses.

Conclusion

At 22 to 29 weeks' gestation, EFW percentile alone poorly predicts perinatal morbidity whether using customized or population fetal growth standards. The population standard diagnoses FGR at increased rates in subgroups not at increased risk of morbidity and at lower rates in subgroups at increased risk of morbidity, whereas the customized standard does not.

Background

The effect of maternal mood disorders on neonatal measurements is not well-defined. The Fetal Growth Studies-Singletons provide a unique opportunity to evaluate the relationship between perceived maternal stress and neonatal growth measurements.

Objective

The purpose of this study was to determine whether perceived maternal stress during pregnancy is associated with anthropometric measurements in the neonate.

Study design

This analysis was based on a prospective, multicenter longitudinal study of fetal growth. Women 18-40 years old with a body mass index of 19.0-29.9 kg/m² were screened at 8+0 to 13+6 weeks gestation for low-risk status associated with optimal fetal growth (eg, healthy, nonsmoking) and underwent serial sonographic examination at 6 study visits throughout gestation. At each study visit, women completed the Cohen's Perceived Stress Survey, which could have a score that ranges from 0-40. We used a latent class trajectory model to identify distinct groupings (ie, classes) of the Perceived Stress Survey trajectories over pregnancy. Trend analysis was used to determine whether neonatal measurements including birthweight, length, head circumference, and abdominal circumference differed by Perceived Stress Survey class and whether this relationship was modified by maternal race/ethnicity, after adjustment for gestational age at delivery, maternal height, age, and parity.

Results

Of the 2334 women enrolled in the study, 1948 women had complete neonatal anthropometry and were included in the analysis. Latent class analysis identified 3 Perceived Stress Survey trajectory classes, with mean Perceived Stress Survey scores of 2.82 (low), 7.95 (medium), and 14.80 (high). Neonatal anthropometric measures of birthweight, length, head circumference and abdominal circumference were similar (P=.78, =.10, =.18, and =.40 respectively), regardless of the participants' Perceived Stress Survey class. There was no effect modification by maternal race/ethnicity.

Conclusion

Neonatal measurements did not differ by levels of perceived stress among low-risk pregnant women.

Objectives

To determine whether longitudinal fetal growth is altered among pregnant women reporting greater perceived stress or more symptoms of depression.

Methods

This analysis was based on a multicenter longitudinal study of fetal growth. Women were screened at gestational ages of 8 weeks to 13 weeks 6 days for low-risk status and underwent serial sonographic examinations. At each study visit during pregnancy, women were asked to complete the Cohen Perceived Stress Scale (PSS) and Edinburgh Postpartum Depression Survey (EPDS). Growth curves for estimated fetal weight and individual biometric parameters were created by using linear mixed models with cubic splines and compared on the basis of whether women scored 15 or higher on the PSS or 10 or higher on the EPDS either at the start of or at any time during pregnancy.

Results

Of the 2334 women enrolled in the study, 2088 (89%) and 2108 (90%) completed the PSS and EPDS, respectively, at least once in all trimesters. The longitudinal growth curves of estimated fetal weight as well as all individual biometric parameters were similar (P > .05) regardless of whether the participants reported PSS of 15 or higher or EPDS of 10 or higher in the first trimester or whether these scores persisted throughout the pregnancy. Similarly, effect modification by race/ethnicity was not statistically significant for the biometric parameters under study (P > .05 for all race/ethnicity interactions).

Conclusions

More depressive symptoms and greater perceived stress, as quantified by the EPDS and the PSS, respectively, are not associated with alterations in fetal growth throughout gestation.

Background

Cell-free DNA (cfDNA) testing for fetal trisomy is highly effective among high-risk women. However, there have been few direct, well-powered studies comparing cfDNA testing with standard screening during the first trimester in routine prenatal populations.

Methods

In this prospective, multicenter, blinded study conducted at 35 international centers, we assigned pregnant women presenting for aneuploidy screening at 10 to 14 weeks of gestation to undergo both standard screening (with measurement of nuchal translucency and biochemical analytes) and cfDNA testing. Participants received the results of standard screening; the results of cfDNA testing were blinded. Determination of the birth outcome was based on diagnostic genetic testing or newborn examination. The primary outcome was the area under the receiver-operating-characteristic curve (AUC) for trisomy 21 (Down's syndrome) with cfDNA testing versus standard screening. We also evaluated cfDNA testing and standard screening to assess the risk of trisomies 18 and 13.

Results

Of 18,955 women who were enrolled, results from 15,841 were available for analysis. The mean maternal age was 30.7 years, and the mean gestational age at testing was 12.5 weeks. The AUC for trisomy 21 was 0.999 for cfDNA testing and 0.958 for standard screening (P=0.001). Trisomy 21 was detected in 38 of 38 women (100%; 95% confidence interval [CI], 90.7 to 100) in the cfDNA-testing group, as compared with 30 of 38 women (78.9%; 95% CI, 62.7 to 90.4) in the standard-screening group (P=0.008). False positive rates were 0.06% (95% CI, 0.03 to 0.11) in the cfDNA group and 5.4% (95% CI, 5.1 to 5.8) in the standard-screening group (P<0.001). The positive predictive value for cfDNA testing was 80.9% (95% CI, 66.7 to 90.9), as compared with 3.4% (95% CI, 2.3 to 4.8) for standard screening (P<0.001).

Conclusions

In this large, routine prenatal-screening population, cfDNA testing for trisomy 21 had higher sensitivity, a lower false positive rate, and higher positive predictive value than did standard screening with the measurement of nuchal translucency and biochemical analytes. (Funded by Ariosa Diagnostics and Perinatal Quality Foundation; NEXT ClinicalTrials.gov number, NCT01511458.).

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