The Effect of Body Mass Index on Post-Bolus Magnesium Levels in the Obstetric Patient.

OBJECTIVE: In the setting of a growing obese obstetric population, we sought to determine whether differences in body mass index (BMI) and obesity class influenced both serum magnesium levels and the likelihood of achieving therapeutic levels for eclampsia prophylaxis after standard boluses of magnesium sulfate. STUDY DESIGN: This is a retrospective cohort study of patients treated with magnesium sulfate in the setting of either preeclampsia with severe features or preterm labor between 2010 and 2016. Subjects were categorized by BMI: Normal (BMI < 30 kg/m2), Class 1 (BMI 30-34.9 kg/m2), Class 2 (BMI 35-39.9 kg/m2), and Class 3 (BMI ≥ 40 kg/m2). Study participants' demographics, intrapartum characteristics, and adverse reactions were compared among the groups. Logistic regression models were used to calculate unadjusted and adjusted odds ratios comparing the likelihood of each BMI class reaching therapeutic eclamptic prophylactic levels. Linear regression models were also evaluated to determine the relationship between BMI and post-bolus serum magnesium levels. RESULTS: Of the 760 people who met the inclusion criteria, 313 (41.1%) had normal BMI, 190 (25.0%) had Class 1 obesity, 135 (17.8%) had Class 2 obesity, and 122 (16.1%) had Class 3 obesity. When adjusted for confounders, those with Class 1 obesity were 54% less likely to achieve serum levels deemed therapeutic for seizure prophylaxis compared with normal BMI counterparts. Meanwhile, those with Class 2 or 3 obesity were 90% less likely. Linear regression models also demonstrated an inverse association between BMI and post-bolus serum magnesium levels. CONCLUSION: Increasing BMI has a significant effect on post-bolus serum magnesium levels regardless of standard loading dose used. Immediately after bolus administration, obese gravidas are significantly less likely to reach levels effective for eclamptic seizure prophylaxis. When considering which bolus to administer in an obese gravida, it may be more beneficial to choose a 6 g load. KEY POINTS: · BMI has an inverse relationship with post-bolus serum magnesium levels.. · Obese gravidas were less likely to reach eclampsia prophylaxis levels regardless of bolus type.. · Obesity class, not just the presence or absence of obesity, plays a role in serum magnesium levels..

Can allostatic load in pregnancy explain the association between race and subsequent cardiovascular disease risk: A cohort study.

OBJECTIVE: To assess the relationship between allostatic load, a measure of cumulative chronic stress in early pregnancy and cardiovascular disease risk, 2-7 years postpartum, and pathways contributing to racial disparities in cardiovascular disease risk. DESIGN: Secondary analysis of a prospective cohort study. SETTING MULTICENTER POPULATION: Pregnant women. METHODS: Our primary exposure was high allostatic load in the first trimester, defined as at least 4 of 12 biomarkers (systolic blood pressure, diastolic blood pressure, body mass index, cholesterol, low-density lipoprotein, high-density lipoprotein, high-sensitivity C-reactive protein, triglycerides, insulin, glucose, creatinine and albumin) in the unfavourable quartile. Logistic regression was used to test the association between high allostatic load and main outcome adjusted for confounders: time from index pregnancy and follow up, age, education, smoking, gravidity, bleeding in the first trimester, index adverse pregnancy outcomes, and health insurance. Each main outcome component and allostatic load were analysed secondarily. Mediation and moderation analyses assessed the role of high allostatic load in racial disparities of cardiovascular disease risk. MAIN OUTCOME MEASURE: Incident cardiovascular disease risk: hypertension, or metabolic disorders. RESULTS: Cardiovascular disease risk was identified in 1462/4022 individuals (hypertension: 36.6%, metabolic disorder: 15.4%). After adjustment, allostatic load was associated with cardiovascular disease risk (adjusted odds ratio [aOR] 2.0, 95% CI 1.8-2.3), hypertension (aOR 2.1, 95% CI 1.8-2.4) and metabolic disorder (aOR 1.7, 95% CI 1.5-2.1). Allostatic load was a partial mediator between race and cardiovascular disease risk. Race did not significantly moderate this relationship. CONCLUSIONS: High allostatic load during pregnancy is associated with cardiovascular disease risk. The relationships between stress, subsequent cardiovascular risk and race warrant further study.

Sleep-disordered Breathing in Pregnancy and after Delivery: Associations with Cardiometabolic Health.

Rationale: Knowledge gaps exist regarding health implications of sleep-disordered breathing (SDB) identified in pregnancy and/or after delivery. Objectives: To determine whether SDB in pregnancy and/or after delivery is associated with hypertension (HTN) and metabolic syndrome (MS). Methods: nuMoM2b-HHS (Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-be Heart Health Study) (N = 4,508) followed participants initially recruited during their first pregnancy. Participants returned for a visit 2-7 years after pregnancy. This study examined a subgroup who underwent SDB assessments during their first pregnancy (n = 1,964) and a repeat SDB assessment after delivery (n = 1,222). Two SDB definitions were considered: 1) apnea-hypopnea index (AHI) ⩾ 5 and 2) oxygen desaturation index (ODI) ⩾ 5. Associations between SDB and incident HTN and MS were evaluated with adjusted risk ratios (aRRs). Measurements and Main Results: The aRR for MS given an AHI ⩾ 5 during pregnancy was 1.44 (95% confidence interval [CI], 1.08-1.93), but no association with HTN was found. ODI ⩾ 5 in pregnancy was associated with both an increased risk for HTN (aRR, 2.02; 95% CI, 1.30-3.14) and MS (aRR, 1.53; 95% CI, 1.19-1.97). Participants with an AHI ⩾ 5 in pregnancy that persisted after delivery were at higher risk for both HTN (aRR, 3.77; 95% CI, 1.84-7.73) and MS (aRR, 2.46; 95% CI, 1.59-3.76). Similar associations were observed for persistent ODI ⩾ 5 after delivery. Conclusions: An AHI ⩾ 5 in pregnancy was associated with an increased risk of MS. An ODI ⩾ 5 in pregnancy was significantly associated with both HTN and MS. Participants with persistent elevations in AHI and ODI during pregnancy and at 2-7 years after delivery were at the highest risk for HTN and MS. Clinical trial registered with www.clinicaltrials.gov (NCT02231398).

Serum Cotinine and Adverse Cardiovascular Outcomes: A Cross-sectional Secondary Analysis of the nuMoM2b Heart Health Study.

OBJECTIVE: We aimed to (1) compare serum cotinine with self-report for ascertaining smoking status among reproductive-aged women; (2) estimate the relative odds of adverse cardiovascular (CV) outcomes among women by smoking status; (3) assess whether the association between adverse pregnancy outcomes (APOs) and CV outcomes varies by smoking status. STUDY DESIGN: We conducted a cross-sectional study of the nuMoM2b Heart Health Study. Women attended a study visit 2 to 7 years after their first pregnancy. The exposure was smoking status, determined by self-report and by serum cotinine. Outcomes included incident chronic hypertension (HTN), metabolic syndrome (MetS), and dyslipidemia. Multivariable logistic regression estimated odds ratios (ORs) for each outcome by smoking status. RESULTS: Of 4,392 women with serum cotinine measured, 3,610 were categorized as nonsmokers, 62 as secondhand smoke exposure, and 720 as smokers. Of 3,144 women who denied tobacco smoke exposure, serum cotinine was consistent with secondhand smoke exposure in 48 (1.5%) and current smoking in 131 (4.2%) After adjustment for APOs, smoking defined by serum cotinine was associated with MetS (adjusted OR [aOR] = 1.52, 95% confidence interval [CI]: 1.21, 1.91) and dyslipidemia (aOR = 1.28, 95% CI: 1.01, 1.62). When stratified by nicotine exposure, nonsmokers with an APO in their index pregnancy had higher odds of stage 1 (aOR = 1.64, 95% CI: 1.32, 2.03) and stage 2 HTN (aOR = 2.92, 95% CI: 2.17, 3.93), MetS (aOR = 1.76, 95% CI: 1.42, 2.18), and dyslipidemia (aOR = 1.55, 95% CI: 1.25, 1.91) relative to women with no APO. Results were similar when smoking exposure was defined by self-report. CONCLUSION: Whether determined by serum cotinine or self-report, smoking is associated with subsequent CV outcomes in reproductive-aged women. APOs are also independently associated with CV outcomes in women. KEY POINTS: · Cotinine was detected in 5.7% of reported nonsmokers.. · Smoking and APOs were independently associated with CV health.. · Smoking was associated with MetS and dyslipidemia..

Association between Sleep Disordered Breathing and Neonatal Outcomes in Nulliparous Individuals.

OBJECTIVE: Our objective was to determine whether objectively measured sleep-disordered breathing (SDB) during pregnancy is associated with an increased risk of adverse neonatal outcomes in a cohort of nulliparous individuals. STUDY DESIGN: Secondary analysis of the nuMom2b sleep disordered breathing substudy was performed. Individuals underwent in-home sleep studies for SDB assessment in early (6-15 weeks' gestation) and mid-pregnancy (22-31 weeks' gestation). SDB was defined as an apnea-hypopnea index ≥5 events/h at either time point. The primary outcome was a composite outcome of respiratory distress syndrome, transient tachypnea of the newborn, or receipt of respiratory support, treated hyperbilirubinemia or hypoglycemia, large-for-gestational age, seizures treated with medications or confirmed by electroencephalography, confirmed sepsis, or neonatal death. Individuals were categorized into (1) early pregnancy SDB (6-15 weeks' gestation), (2) new onset mid-pregnancy SDB (22-31 weeks' gestation), and (3) no SDB. Log-binomial regression was used to calculate adjusted risk ratios (RR) and 95% confidence intervals (CIs) representing the association. RESULTS: Among 2,106 participants, 3% (n = 75) had early pregnancy SDB and 5.7% (n = 119) developed new-onset mid-pregnancy SDB. The incidence of the primary outcome was higher in the offspring of individuals with early (29.3%) and new onset mid-pregnancy SDB (30.3%) compared with individuals with no SDB (17.8%). After adjustment for maternal age, chronic hypertension, pregestational diabetes, and body mass index, new onset mid-pregnancy SDB conferred increased risk (RR = 1.43, 95% CI: 1.05, 1.94), where there was no longer statistically significant association between early pregnancy SDB and the primary outcome. CONCLUSION: New onset, mid-pregnancy SDB is independently associated with neonatal morbidity. KEY POINTS: · Sleep disordered breathing (SDB) is a common condition impacting pregnancy with known maternal risks.. · Objectively defined SDB in pregnancy was associated with a composite of adverse neonatal outcomes.. · New onset SDB in mid pregnancy conferred statistically significant increased risk..

Cannabis Exposure and Adverse Pregnancy Outcomes Related to Placental Function.

Importance: Cannabis use is increasing among reproductive-age individuals and the risks associated with cannabis exposure during pregnancy remain uncertain. Objective: To evaluate the association between maternal cannabis use and adverse pregnancy outcomes known to be related to placental function. Design, Setting, and Participants: Ancillary analysis of nulliparous individuals treated at 8 US medical centers with stored urine samples and abstracted pregnancy outcome data available. Participants in the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be cohort were recruited from 2010 through 2013; the drug assays and analyses for this ancillary project were completed from June 2020 through April 2023. Exposure: Cannabis exposure was ascertained by urine immunoassay for 11-nor-9-carboxy-Δ9-tetrahydrocannabinol using frozen stored urine samples from study visits during the pregnancy gestational age windows of 6 weeks and 0 days to 13 weeks and 6 days (visit 1); 16 weeks and 0 days to 21 weeks and 6 days (visit 2); and 22 weeks and 0 days to 29 weeks and 6 days (visit 3). Positive results were confirmed with liquid chromatography tandem mass spectrometry. The timing of cannabis exposure was defined as only during the first trimester or ongoing exposure beyond the first trimester. Main Outcome and Measure: The dichotomous primary composite outcome included small-for-gestational-age birth, medically indicated preterm birth, stillbirth, or hypertensive disorders of pregnancy ascertained by medical record abstraction by trained perinatal research staff with adjudication of outcomes by site investigators. Results: Of 10 038 participants, 9257 were eligible for this analysis. Of the 610 participants (6.6%) with cannabis use, 32.4% (n = 197) had cannabis exposure only during the first trimester and 67.6% (n = 413) had ongoing exposure beyond the first trimester. Cannabis exposure was associated with the primary composite outcome (25.9% in the cannabis exposure group vs 17.4% in the no exposure group; adjusted relative risk, 1.27 [95% CI, 1.07-1.49]) in the propensity score-weighted analyses after adjustment for sociodemographic characteristics, body mass index, medical comorbidities, and active nicotine use ascertained via urine cotinine assays. In a 3-category cannabis exposure model (no exposure, exposure only during the first trimester, or ongoing exposure), cannabis use during the first trimester only was not associated with the primary composite outcome; however, ongoing cannabis use was associated with the primary composite outcome (adjusted relative risk, 1.32 [95% CI, 1.09-1.60]). Conclusions and Relevance: In this multicenter cohort, maternal cannabis use ascertained by biological sampling was associated with adverse pregnancy outcomes related to placental dysfunction.

Placental protein levels in maternal serum are associated with adverse pregnancy outcomes in nulliparous patients.

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.

Factors associated with duration of breastfeeding in women giving birth for the first time.

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).

The impact of setting a pregnancy weight gain goal on total weight gain.

BACKGROUND: Expert groups recommend that women set a pregnancy weight gain goal with their care provider to optimise weight gain. OBJECTIVE: Our aim was to describe the concordance between first-trimester personal and provider pregnancy weight gain goals with the Institute of Medicine (IOM) recommendations and to determine the association between these goals and total weight gain. METHODS: We used data from 9353 women in the Nulliparous Pregnancy Outcomes Study: monitoring mothers-to-be. In the first trimester, women reported their personal pregnancy weight gain goal and their provider weight gain goal, and we categorised personal and provider weight gain goals and total weight gain according to IOM recommendations. We used log-binomial or linear regression models to relate goals to total weight gain, adjusting for confounders including race/ethnicity, maternal age, education, smoking, marital status and planned pregnancy. RESULTS: Approximately 37% of women reported no weight gain goals, while 24% had personal and provider goals, 31% had only a personal goal, and 8% had only a provider goal. Personal and provider goals were outside the recommended ranges in 12%-23% of normal-weight women, 31%-41% of overweight women and 47%-63% of women with obesity. Women with both personal and provider pregnancy weight gain goals were 6%-14% more likely than their counterparts to have a goal within IOM-recommended ranges. Having any goal or a goal within the IOM-recommended ranges was unrelated to pregnancy weight gain. Excessive weight gain occurred in approximately half of normal-weight or obese women and three-quarters of overweight women, regardless of goal setting group. CONCLUSIONS: These findings do not support the effectiveness of early-pregnancy personal or provider gestational weight gain goal setting alone in optimising weight gain. Multifaceted interventions that address a number of mediators of goal setting success may assist women in achieving weight gain consistent with their goals.

Is Exposure to Intrapartum Prostaglandins for Labor Induction Associated with a Lower Incidence of Neonatal Respiratory Distress Syndrome?

OBJECTIVE: Respiratory distress syndrome (RDS) is implicated in 30% of neonatal deaths. Since prostaglandins promote surfactant secretion and labor is associated with a lower risk of RDS in term neonates, it is plausible that synthetic prostaglandin (sPG) exposure is associated with a lower risk of RDS. Thus, we evaluated the association between sPG exposure and RDS in neonates born after the induction of labor (IOL). STUDY DESIGN: Secondary analysis of women with singleton pregnancies undergoing IOL at 340/7 to 420/7 weeks in the nuMoM2b study, a multicenter prospective cohort of nulliparous women. RDS rates and secondary neonatal outcomes in neonates with intrapartum sPG exposure were compared with those who had IOL with non-sPG methods (e.g., balloon catheter, amniotomy, oxytocin, and laminaria). Logistic regression models estimated the association of sPG with RDS and with secondary outcomes after adjustment for clinical and demographic factors (including gestational age). A sensitivity analysis was performed in which analysis was restricted to those with an admission cervical dilation ≤2 cm. RESULTS: Of 10,038 women in the total cohort, 3,071 met inclusion criteria; 1,444 were exposed and 1,627 were unexposed to sPGs. Antenatal corticosteroid exposure rates were low (3.0%) and similar between groups. In univariable analysis, neonates with sPG exposure had higher rates of RDS (3.2 vs. 2.0%, odds ratio [OR]: 1.59, 95% confidence interval [CI]: 1.01-2.50). This relationship was similar by gestational age at delivery (term vs. preterm, interaction p = 0.14). After adjustment, the association between sPG and RDS was no longer significant (adjusted odds ratio: 1.4, 95% CI: 0.9-2.3). When analysis was restricted to subjects with admission cervical dilation of ≤2 cm, there was also no association between sPG exposure and RDS. CONCLUSION: In pregnancies between 34 and 42 weeks of gestation, exposure to sPG for cervical ripening or labor induction was not associated with newborn RDS. KEY POINTS: · RDS is implicated in 30% of neonatal deaths.. · sPG exposure was not associated with RDS.. · Avoiding preterm birth remains crucial in RDS prevention..

Antenatal Fetal Adrenal Measurements at 22 to 30 Weeks' Gestation, Fetal Growth Restriction, and Perinatal Morbidity.

OBJECTIVE: Our objective was to test the association of fetal adrenal size with perinatal morbidity among fetuses with fetal growth restriction (FGR; estimated fetal weight [EFW] < 10th percentile). STUDY DESIGN: This was a secondary analysis of the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-be (nuMoM2b) adrenal study, which measured fetal adrenal gland size at 22 to 30 weeks' gestation. We analyzed the transverse adrenal area (TAA) and fetal zone area (absolute measurements and corrected for fetal size) and the ratio of the fetal zone area to the total transverse area using a composite perinatal outcome of stillbirth, neonatal intensive care unit admission, respiratory distress syndrome, necrotizing enterocolitis, retinopathy of prematurity, sepsis, mechanical ventilation, seizure, or death. Among fetuses with FGR, adrenal measurements were compared between those that did and did not experience the composite perinatal outcome. RESULTS: There were 1,709 eligible neonates. Seven percent (n = 120) were diagnosed with FGR at the time of adrenal measurement, and 14.7% (n = 251) experienced perinatal morbidity. EFW-corrected and absolute adrenal measurements were similar among fetuses with and without FGR as well as among those who did and did not experience morbidity. The area under the curve for corrected TAA was 0.52 (95% confidence interval 0.38-0.67). CONCLUSION: In our cohort, adrenal size was not associated with risk of morbidity among fetuses with FGR.

Customized versus Population Growth Standards for Morbidity and Mortality Risk Stratification Using Ultrasonographic Fetal Growth Assessment at 22 to 29 Weeks' Gestation.

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.

Associations of perceived prenatal stress and adverse pregnancy outcomes with perceived stress years after delivery.

Maternal stress is a risk factor for adverse pregnancy outcomes (APOs). This study evaluates the associations of prenatal stress and APOs with maternal stress years after pregnancy. The 10-item Perceived Stress Scale (PSS) (0-40 range) was completed in the first and third trimesters, and 2-7 years after delivery among a subsample (n = 4161) of nulliparous women enrolled at eight US medical centers between 2010 and 2013 in a prospective, observational cohort study. Demographics, medical history, and presence of APOs (gestational diabetes (GDM), hypertensive disorders of pregnancy (HDP), preeclampsia (PE), and medically indicated or spontaneous preterm birth (miPTB, sPTB)) were obtained. The associations of prenatal PSS and the presence of APOs with PSS scores years after delivery were estimated using multivariable linear regression. Mean PSS scores were 12.5 (95% CI 12.3, 12.7) and 11.3 (95% CI 11.1, 11.5) in the first and third trimesters respectively and 14.9 (95% CI 14.7, 15.1) 2-7 years later, an average increase of 2.4 points (95% CI 2.2, 2.6) from the start of pregnancy. Regressing PSS scores after delivery on first-trimester PSS and PSS increase through pregnancy showed positive associations, with coefficients (95% CI) of 2.8 (2.7, 3.0) and 1.5 (1.3, 1.7) per 5-point change, respectively. Adding APO indicator variables separately showed higher PSS scores for women with HDP (0.7 [0.1, 1.3]), PE (1.3 [0.6, 2.1]), and miPTB (1.3 [0.2, 2.4]), but not those with GDM or sPTB. In this geographically and demographically diverse sample, prenatal stress and some APOs were positively associated with stress levels 2-7 years after pregnancy.ClinicalTrials.gov Registration number NCT02231398.

Gestational weight gain across continents and ethnicity: systematic review and meta-analysis of maternal and infant outcomes in more than one million women.

BACKGROUND: The association between Institute of Medicine (IOM) guidelines and pregnancy outcomes across ethnicities is uncertain. We evaluated the associations of gestational weight gain (GWG) outside 2009 IOM guidelines, with maternal and infant outcomes across the USA, western Europe and east Asia, with subgroup analyses in Asia. The aim was to explore ethnic differences in maternal prepregnancy body mass index (BMI), GWG and health outcomes across these regions. METHODS: Systematic review, meta-analysis and meta-regression of observational studies were used for the study. MEDLINE, MEDLINE In-Process, Embase and all Evidence-Based Medicine (EBM) Reviews were searched from 1999 to 2017. Studies were stratified by prepregnancy BMI category and total pregnancy GWG. Odds ratio (ORs) 95% confidence intervals (CI) applied recommended GWG within each BMI category as the reference. Primary outcomes were small for gestational age (SGA), preterm birth and large for gestational age (LGA). Secondary outcomes were macrosomia, caesarean section and gestational diabetes. RESULTS: Overall, 5874 studies were identified and 23 were included (n = 1,309,136). Prepregnancy overweight/obesity in the USA, Europe and Asia was measured at 42%, 30% and 10% respectively, with underweight 5%, 3% and 17%. GWG below guidelines in the USA, Europe and Asia was 21%, 18% and 31%, and above was 51%, 51% and 37% respectively. Applying regional BMI categories in Asia showed GWG above guidelines (51%) was similar to that in the USA and Europe. GWG below guidelines was associated with a higher risk of SGA (USA/Europe [OR 1.51; CI 1.39, 1.63]; Asia [1.63; 1.45, 1.82]) and preterm birth (USA/Europe [1.35; 1.17, 1.56]; Asia [1.06; 0.78, 1.44]) than GWG within guidelines. GWG above guidelines was associated with a higher risk of LGA (USA/Europe [1.93; 1.81, 2.06]; Asia [1.68; 1.51 , 1.87]), macrosomia (USA/Europe [1.87; 1.70, 2.06]; Asia [2.18; 1.91, 2.49]) and caesarean (USA/Europe [1.26; 1.21, 1.33]; Asia [1.37; 1.30, 1.45]). Risks remained elevated when regional BMI categories were applied for GWG recommendations. More women in Asia were categorised as having GWG below guidelines using World Health Organization (WHO) (60%) compared to regional BMI categories (16%), yet WHO BMI was not accompanied by increased risks of adverse outcomes. CONCLUSIONS: Women in the USA and western Europe have higher prepregnancy BMI and higher rates of GWG above guidelines than women in east Asia. However, when using regional BMI categories in east Asia, rates of GWG above guidelines are similar across the three continents. GWG outside guidelines is associated with adverse outcomes across all regions. If regional BMI categories are used in east Asia, IOM guidelines are applicable in the USA, western Europe and east Asia.

Predictors of sleep-disordered breathing in pregnancy.

BACKGROUND: Sleep-disordered breathing (SDB) is common in pregnancy, but there are limited data on predictors. OBJECTIVES: The objective of this study was to develop predictive models of sleep-disordered breathing during pregnancy. STUDY DESIGN: Nulliparous women completed validated questionnaires to assess for symptoms related to snoring, fatigue, excessive daytime sleepiness, insomnia, and restless leg syndrome. The questionnaires included questions regarding the timing of sleep and sleep duration, work schedules (eg, shift work, night work), sleep positions, and previously diagnosed sleep disorders. Frequent snoring was defined as self-reported snoring ≥3 days per week. Participants underwent in-home portable sleep studies for sleep-disordered breathing assessment in early (6-15 weeks gestation) and mid pregnancy (22-31 weeks gestation). Sleep-disordered breathing was characterized by an apnea hypopnea index that included all apneas, plus hypopneas with ≥3% oxygen desaturation. For primary analyses, an apnea hypopnea index ≥5 events per hour was used to define sleep-disordered breathing. Odds ratios and 95% confidence intervals were calculated for predictor variables. Predictive ability of the logistic models was estimated with area under the receiver-operating-characteristic curves, along with sensitivities, specificities, and positive and negative predictive values and likelihood ratios. RESULTS: Among 3705 women who were enrolled, data were available for 3264 and 2512 women in early and mid pregnancy, respectively. The corresponding prevalence of sleep-disordered breathing was 3.6% and 8.3%, respectively. At each time point in gestation, frequent snoring, chronic hypertension, greater maternal age, body mass index, neck circumference, and systolic blood pressure were associated most strongly with an increased risk of sleep-disordered breathing. Logistic regression models that included current age, body mass index, and frequent snoring predicted sleep-disordered breathing in early pregnancy, sleep-disordered breathing in mid pregnancy, and new onset sleep-disordered breathing in mid pregnancy with 10-fold cross-validated area under the receiver-operating-characteristic curves of 0.870, 0.838, and 0.809. We provide a supplement with expanded tables, integrated predictiveness, classification curves, and an predicted probability calculator. CONCLUSION: Among nulliparous pregnant women, logistic regression models with just 3 variables (ie, age, body mass index, and frequent snoring) achieved good prediction of prevalent and incident sleep-disordered breathing. These results can help with screening for sleep-disordered breathing in the clinical setting and for future clinical treatment trials.

Patterns of leisure-time physical activity across pregnancy and adverse pregnancy outcomes.

BACKGROUND: Although leisure-time physical activity (PA) contributes to overall health, including pregnancy health, patterns across pregnancy have not been related to birth outcomes. We hypothesized that women with sustained low leisure-time PA would have excess risk of adverse pregnancy outcomes, and that changing patterns across pregnancy (high to low and low to high) may also be related to risk of adverse pregnancy outcomes. METHODS: Nulliparous women (n = 10,038) were enrolled at 8 centers early in pregnancy (mean gestational age in weeks [SD] = 12.05 [1.51]. Frequency, duration, and intensity (metabolic equivalents) of up to three leisure activities reported in the first, second and third trimesters were analyzed. Growth mixture modeling was used to identify leisure-time PA patterns across pregnancy. Adverse pregnancy outcomes (preterm birth, [PTB, overall and spontaneous], hypertensive disorders of pregnancy [HDP], gestational diabetes [GDM] and small-for-gestational-age births [SGA]) were assessed via chart abstraction. RESULTS: Five patterns of leisure-time PA across pregnancy were identified: High (35%), low (18%), late decreasing (24%), early decreasing (10%), and early increasing (13%). Women with sustained low leisure-time PA were younger and more likely to be black or Hispanic, obese, or to have smoked prior to pregnancy. Women with low vs. high leisure-time PA patterns had higher rates of PTB (10.4 vs. 7.5), HDP (13.9 vs. 11.4), and GDM (5.7 vs. 3.1, all p < 0.05). After adjusting for maternal factors (age, race/ethnicity, BMI and smoking), the risk of GDM (Odds ratio 2.00 [95% CI 1.47, 2.73]) remained higher in women with low compared to high patterns. Early and late decreasing leisure-time PA patterns were also associated with higher rates of GDM. In contrast, women with early increasing patterns had rates of GDM similar to the group with high leisure-time PA (3.8% vs. 3.1%, adjusted OR 1.16 [0.81, 1.68]). Adjusted risk of overall PTB (1.31 [1.05, 1.63]) was higher in the low pattern group, but spontaneous PTB, HDP and SGA were not associated with leisure-time PA patterns. CONCLUSIONS: Sustained low leisure-time PA across pregnancy is associated with excess risk of GDM and overall PTB compared to high patterns in nulliparous women. Women with increased leisure-time PA early in pregnancy had low rates of GDM that were similar to women with high patterns, raising the possibility that early pregnancy increases in activity may be associated with improved pregnancy health. TRIAL REGISTRATION: Registration number NCT02231398 .

Source Characterization and Exposure Modeling of Gas-Phase Polycyclic Aromatic Hydrocarbon (PAH) Concentrations in Southern California.

Airborne exposures to polycyclic aromatic hydrocarbons (PAHs) are associated with adverse health outcomes. Because personal air measurements of PAHs are labor intensive and costly, spatial PAH exposure models are useful for epidemiological studies. However, few studies provide adequate spatial coverage to reflect intra-urban variability of ambient PAHs. In this study, we collected 39-40 weekly gas-phase PAH samples in southern California twice in summer and twice in winter, 2009, in order to characterize PAH source contributions and develop spatial models that can estimate gas-phase PAH concentrations at a high resolution. A spatial mixed regression model was constructed, including such variables as roadway, traffic, land-use, vegetation index, commercial cooking facilities, meteorology, and population density. Cross validation of the model resulted in an R2 of 0.66 for summer and 0.77 for winter. Results showed higher total PAH concentrations in winter. Pyrogenic sources, such as fossil fuels and diesel exhaust, were the most dominant contributors to total PAHs. PAH sources varied by season, with a higher fossil fuel and wood burning contribution in winter. Spatial autocorrelation accounted for a substantial amount of the variance in total PAH concentrations for both winter (56%) and summer (19%). In summer, other key variables explaining the variance included meteorological factors (9%), population density (15%), and roadway length (21%). In winter, the variance was also explained by traffic density (16%). In this study, source characterization confirmed the dominance of traffic and other fossil fuel sources to total measured gas-phase PAH concentrations while a spatial exposure model identified key predictors of PAH concentrations. Gas-phase PAH source characterization and exposure estimation is of high utility to epidemiologist and policy makers interested in understanding the health impacts of gas-phase PAHs and strategies to reduce emissions.

Objectively measured short sleep duration and later sleep midpoint in pregnancy are associated with a higher risk of gestational diabetes.

BACKGROUND: Experimental and epidemiologic data suggest that among nonpregnant adults, sleep duration may be an important risk factor for chronic disease. Although pregnant women commonly report poor sleep, few studies objectively evaluated the quality of sleep in pregnancy or explored the relationship between sleep disturbances and maternal and perinatal outcomes. OBJECTIVE: Our objective was to examine the relationship between objectively assessed sleep duration, timing, and continuity (measured via wrist actigraphy) and maternal cardiovascular and metabolic morbidity specific to pregnancy. STUDY DESIGN: This was a prospective cohort study of nulliparous women. Women were recruited between 16 0/7 and 21 6/7 weeks' gestation. They were asked to wear a wrist actigraphy monitor and complete a daily sleep log for a period of 7 consecutive days. The primary sleep exposure variables were the averages of the following over the total valid nights (minimum 5, maximum 7 nights): short sleep duration during the primary sleep period (<7 h/night), late sleep midpoint (midpoint between sleep onset and sleep offset >5 am), and top quartile of minutes of wake time after sleep onset and sleep fragmentation index. The primary outcomes of interest were a composite of hypertensive disorders of pregnancy (mild, severe, or superimposed preeclampsia; eclampsia; or antepartum gestational hypertension) and gestational diabetes mellitus. We used χ2 tests to assess associations between sleep variables and categorical baseline characteristics. Crude odds ratios and 95% confidence intervals were estimated from univariate logistic regression models to characterize the magnitude of the relationship between sleep characteristics and hypertensive disorders of pregnancy and gestational diabetes. For associations significant in univariate analysis, multiple logistic regression was used to explore further the association of sleep characteristics with pregnancy outcomes. RESULTS: In all, 901 eligible women consented to participate; 782 submitted valid actigraphy studies. Short sleep duration and a later sleep midpoint were associated with an increased risk of gestational diabetes (odds ratio, 2.24; 95% confidence interval, 1.11-4.53; and odds ratio, 2.58; 95% confidence interval, 1.24-5.36, respectively) but not of hypertensive disorders. A model with both sleep duration and sleep midpoint as well as their interaction term revealed that while there was no significant interaction between these exposures, the main effects of both short sleep duration and later sleep midpoint with gestational diabetes remained significant (adjusted odds ratio, 2.06; 95% confidence interval, 1.01-4.19; and adjusted odds ratio, 2.37; 95% confidence interval, 1.13-4.97, respectively). Additionally, after adjusting separately for age, body mass index, and race/ethnicity, both short sleep duration and later sleep midpoint remained associated with gestational diabetes. No associations were demonstrated between the sleep quality measures (wake after sleep onset, sleep fragmentation) and hypertensive disorders or gestational diabetes. CONCLUSION: Our results demonstrate a relationship between short sleep duration and later sleep midpoint with gestational diabetes. Our data suggest independent contributions of these 2 sleep characteristics to the risk for gestational diabetes in nulliparous women.

Association of Gestational Weight Gain With Maternal and Infant Outcomes: A Systematic Review and Meta-analysis.

IMPORTANCE: Body mass index (BMI) and gestational weight gain are increasing globally. In 2009, the Institute of Medicine (IOM) provided specific recommendations regarding the ideal gestational weight gain. However, the association between gestational weight gain consistent with theIOM guidelines and pregnancy outcomes is unclear. OBJECTIVE: To perform a systematic review, meta-analysis, and metaregression to evaluate associations between gestational weight gain above or below the IOM guidelines (gain of 12.5-18 kg for underweight women [BMI <18.5]; 11.5-16 kg for normal-weight women [BMI 18.5-24.9]; 7-11 kg for overweight women [BMI 25-29.9]; and 5-9 kg for obese women [BMI ≥30]) and maternal and infant outcomes. DATA SOURCES AND STUDY SELECTION: Search of EMBASE, Evidence-Based Medicine Reviews, MEDLINE, and MEDLINE In-Process between January 1, 1999, and February 7, 2017, for observational studies stratified by prepregnancy BMI category and total gestational weight gain. DATA EXTRACTION AND SYNTHESIS: Data were extracted by 2 independent reviewers. Odds ratios (ORs) and absolute risk differences (ARDs) per live birth were calculated using a random-effects model based on a subset of studies with available data. MAIN OUTCOMES AND MEASURES: Primary outcomes were small for gestational age (SGA), preterm birth, and large for gestational age (LGA). Secondary outcomes were macrosomia, cesarean delivery, and gestational diabetes mellitus. RESULTS: Of 5354 identified studies, 23 (n = 1 309 136 women) met inclusion criteria. Gestational weight gain was below or above guidelines in 23% and 47% of pregnancies, respectively. Gestational weight gain below the recommendations was associated with higher risk of SGA (OR, 1.53 [95% CI, 1.44-1.64]; ARD, 5% [95% CI, 4%-6%]) and preterm birth (OR, 1.70 [1.32-2.20]; ARD, 5% [3%-8%]) and lower risk of LGA (OR, 0.59 [0.55-0.64]; ARD, -2% [-10% to -6%]) and macrosomia (OR, 0.60 [0.52-0.68]; ARD, -2% [-3% to -1%]); cesarean delivery showed no significant difference (OR, 0.98 [0.96-1.02]; ARD, 0% [-2% to 1%]). Gestational weight gain above the recommendations was associated with lower risk of SGA (OR, 0.66 [0.63-0.69]; ARD, -3%; [-4% to -2%]) and preterm birth (OR, 0.77 [0.69-0.86]; ARD, -2% [-2% to -1%]) and higher risk of LGA (OR, 1.85 [1.76-1.95]; ARD, 4% [2%-5%]), macrosomia (OR, 1.95 [1.79-2.11]; ARD, 6% [4%-9%]), and cesarean delivery (OR, 1.30 [1.25-1.35]; ARD, 4% [3%-6%]). Gestational diabetes mellitus could not be evaluated because of the nature of available data. CONCLUSIONS AND RELEVANCE: In this systematic review and meta-analysis of more than 1 million pregnant women, 47% had gestational weight gain greater than IOM recommendations and 23% had gestational weight gain less than IOM recommendations. Gestational weight gain greater than or less than guideline recommendations, compared with weight gain within recommended levels, was associated with higher risk of adverse maternal and infant outcomes.