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BACKGROUND: Epidemiological findings regarding the association of particulate matter ≤2.5 μm (PM2.5) exposure with hypertensive disorders in pregnancy (HDP) are inconsistent; evidence for HDP risk related to PM2.5 components, mixture effects, and windows of susceptibility is limited. We aimed to investigate the relationships between HDP and exposure to PM2.5 during pregnancy. METHODS AND FINDINGS: A large retrospective cohort study was conducted among mothers with singleton pregnancies in Kaiser Permanente Southern California from 2008 to 2017. HDP were defined by International Classification of Diseases-9/10 (ICD-9/10) diagnostic codes and were classified into 2 subcategories based on the severity of HDP: gestational hypertension (GH) and preeclampsia and eclampsia (PE-E). Monthly averages of PM2.5 total mass and its constituents (i.e., sulfate, nitrate, ammonium, organic matter, and black carbon) were estimated using outputs from a fine-resolution geoscience-derived model. Multilevel Cox proportional hazard models were used to fit single-pollutant models; quantile g-computation approach was applied to estimate the joint effect of PM2.5 constituents. The distributed lag model was applied to estimate the association between monthly PM2.5 exposure and HDP risk. This study included 386,361 participants (30.3 ± 6.1 years) with 4.8% (17,977/373,905) GH and 5.0% (19,381/386,361) PE-E cases, respectively. In single-pollutant models, we observed increased relative risks for PE-E associated with exposures to PM2.5 total mass [adjusted hazard ratio (HR) per interquartile range: 1.07, 95% confidence interval (CI) [1.04, 1.10] p < 0.001], black carbon [HR = 1.12 (95% CI [1.08, 1.16] p < 0.001)] and organic matter [HR = 1.06 (95% CI [1.03, 1.09] p < 0.001)], but not for GH. The population attributable fraction for PE-E corresponding to the standards of the US Environmental Protection Agency (9 μg/m3) was 6.37%. In multi-pollutant models, the PM2.5 mixture was associated with an increased relative risk of PE-E ([HR = 1.05 (95% CI [1.03, 1.07] p < 0.001)], simultaneous increase in PM2.5 constituents of interest by a quartile) and PM2.5 black carbon gave the greatest contribution of the overall mixture effects (71%) among all individual constituents. The susceptible window is the late first trimester and second trimester. Furthermore, the risks of PE-E associated with PM2.5 exposure were significantly higher among Hispanic and African American mothers and mothers who live in low- to middle-income neighborhoods (p < 0.05 for Cochrans Q test). Study limitations include potential exposure misclassification solely based on residential outdoor air pollution, misclassification of disease status defined by ICD codes, the date of diagnosis not reflecting the actual time of onset, and lack of information on potential covariates and unmeasured factors for HDP. CONCLUSIONS: Our findings add to the literature on associations between air pollution exposure and HDP. To our knowledge, this is the first study reporting that specific air pollution components, mixture effects, and susceptible windows of PM2.5 may affect GH and PE-E differently.

Gestational diabetes mellitus (GDM) is a major pregnancy complication affecting approximately 14.0% of pregnancies around the world. Air pollution exposure, particularly exposure to PM2.5, has become a major environmental issue affecting health, especially for vulnerable pregnant women. Associations between PM2.5 exposure and adverse birth outcomes are generally assumed to be the same throughout a large geographical area. However, the effects of air pollution on health can very spatially in subpopulations. Such spatially varying effects are likely due to a wide range of contextual neighborhood and individual factors that are spatially correlated, including SES, demographics, exposure to housing characteristics and due to different composition of particulate matter from different emission sources. This combination of elevated environmental hazards in conjunction with socioeconomic-based disparities forms what has been described as a double jeopardy for marginalized sub-populations. In this manuscript our analysis combines both an examination of spatially varying effects of a) unit-changes in exposure and examines effects of b) changes from current exposure levels down to a fixed compliance level, where compliance levels correspond to the Air Quality Standards (AQS) set by the U.S. Environmental Protection Agency (EPA) and World Health Organization (WHO) air quality guideline values. Results suggest that exposure reduction policies should target certain hotspot areas where size and effects of potential reductions will reap the greatest rewards in terms of health benefits, such as areas of southeast Los Angeles County which experiences high levels of PM2.5 exposures and consist of individuals who may be particularly vulnerable to the effects of air pollution on the risk of GDM.

BACKGROUND: Significant mortality and morbidity in pregnant women and their offspring are linked to premature rupture of membranes (PROM). Epidemiological evidence for heat-related PROM risk is extremely limited. We investigated associations between acute heatwave exposure and spontaneous PROM. METHODS: We conducted this retrospective cohort study among mothers in Kaiser Permanente Southern California who experienced membrane ruptures during the warm season (May-September) from 2008 to 2018. Twelve definitions of heatwaves with different cut-off percentiles (75th, 90th, 95th, and 98th) and durations (≥ 2, 3, and 4 consecutive days) were developed using the daily maximum heat index, which incorporates both daily maximum temperature and minimum relative humidity in the last gestational week. Cox proportional hazards models were fitted separately for spontaneous PROM, term PROM (TPROM), and preterm PROM (PPROM) with zip codes as the random effect and gestational week as the temporal unit. Effect modification by air pollution (i.e., PM2.5 and NO2), climate adaptation measures (i.e., green space and air conditioning [AC] penetration), sociodemographic factors, and smoking behavior was examined. RESULTS: In total, we included 190,767 subjects with 16,490 (8.6%) spontaneous PROMs. We identified a 9-14% increase in PROM risks associated with less intense heatwaves. Similar patterns as PROM were found for TPROM and PPROM. The heat-related PROM risks were greater among mothers exposed to a higher level of PM2.5 during pregnancy, under 25 years old, with lower education and household income level, and who smoked. Even though climate adaptation factors were not statistically significant effect modifiers, mothers living with lower green space or lower AC penetration were at consistently higher heat-related PROM risks compared to their counterparts. CONCLUSION: Using a rich and high-quality clinical database, we detected harmful heat exposure for spontaneous PROM in preterm and term deliveries. Some subgroups with specific characteristics were more susceptible to heat-related PROM risk.

BackgroundEpidemiological findings are inconsistent regarding the associations between air pollution exposure during pregnancy and gestational diabetes mellitus (GDM). Several limitations exist in previous studies, including potential outcome and exposure misclassification, unassessed confounding, and lack of simultaneous consideration of air pollution mixtures and particulate matter (PM) constituents.ObjectivesTo assess the association between GDM and maternal residential exposure to air pollution, and the joint effect of the mixture of air pollutants and PM constituents.MethodsDetailed clinical data were obtained for 395,927 pregnancies in southern California (2008-2018) from Kaiser Permanente Southern California (KPSC) electronic health records. GDM diagnosis was based on KPSC laboratory tests. Monthly average concentrations of fine particulate matter

Objective Recent studies have reported associations between severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection during pregnancy and adverse perinatal outcomes but the extent to which these associations vary by race/ethnicity remains uncertain. Therefore, we examined how the association between prenatal SARS-CoV-2 infection and adverse perinatal outcomes may be modified by race/ethnicity. Study Design A retrospective cohort study was performed using data on 67,986 pregnant women extracted from the Kaiser Permanente Southern California electronic health records between April 6, 2020, and December 31, 2021. Upon admission to labor and delivery, all women were routinely tested for coronavirus disease 2019 (COVID-19) using real-time reverse-transcriptase polymerase chain reaction test. Adjusted odds ratios (aORs) were used to estimate associations. Results During the study period, COVID-19 was diagnosed in 4,960 (7%) of singleton pregnancies, with the highest rates observed among Hispanics (9.4%) and non-Hispanic Blacks (6.2%). Compared with non-Hispanic Whites, Hispanics (aOR: 1.12, 95% CI: 1.03, 1.21) with SARS-CoV-2 infection had the highest odds of a pregnancy associated with nonreassuring fetal heart rate tracing. Neonates of all races/ethnicities, except for non-Hispanic Blacks, showed significantly increased odds of SARS-CoV-2 infection, with the highest risk observed among Asians/Pacific Islanders (aOR: 10.88, 95% CI: 1.33, 89.04). Non-Hispanic White mothers who tested positive were admitted to intensive care unit (ICU) at a higher rate at delivery and within 7 days of delivery (aOR: 34.77, 95% CI: 11.3, 107.04; aOR: 26.48, 95% CI: 9.55, 73.46, respectively). Hispanics were also at a significantly higher odds of admission to ICU (aOR: 4.62, 95% CI: 2.69, 7.94; aOR: 4.42, 95% CI: 2.58, 7.56, respectively). Non-Hispanic Black, Hispanic, and Asian/Pacific Islander mothers who tested positive for SARS-CoV-2 prenatally, were at increased risk for preeclampsia/eclampsia, and preterm birth as compared to non-Hispanic White mothers. Conclusion The findings highlight racial/ethnic disparities in the association between SARS-CoV-2 infection and adverse perinatal outcomes. The risk of neonatal SARS-CoV-2 infection was highest for Asian/Pacific Islanders. We also observed a remarkably high risk of ICU admission for non-Hispanic White mothers infected with SARS-CoV-2. Key Points Race/ethnicity influences perinatal outcomes in pregnancies impacted by SARS-CoV-2. The risk of neonatal SARS-CoV-2 infection was highest for Asian/Pacific Islanders. White mothers had a notably high risk of ICU admission at delivery following SARS-CoV-2 infection. [ABSTRACT FROM AUTHOR]

Objective This study aimed to examine whether severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection during pregnancy is associated with increased odds of perinatal complications and viral transmission to the infant. Study Design A retrospective cohort study of women who delivered at Kaiser Permanente Southern California hospitals (April 6, 2020–February 28, 2021) was performed using data extracted from electronic health records (EHRs). During this time polymerize chain reaction (PCR)-based tests for SARS-CoV-2 was universally offered to all pregnant women at labor and delivery admission, as well as earlier in the pregnancy, if they were displaying symptoms consistent with SARS-CoV-2 infection or a possible exposure to the virus. Adjusted odds ratio (aOR) was used to estimate the strength of associations between positive test results and adverse perinatal outcomes. Results Of 35,123 women with a singleton pregnancy, 2,203 (6%) tested positive for SARS-CoV-2 infection with 596 (27%) testing positive during the first or second trimester and 1,607 (73%) during the third trimester. Women testing positive were younger than those who tested negative (29.7 [5.4] vs. 31.1 [5.3] years; mean [standard deviation (SD)]; p <.001). The SARS-CoV-2 infection tended to increase the odds of an abnormal fetal heart rate pattern (aOR: 1.10; 95% confidence interval [CI]: 1.00, 1.21; p = 0.058), spontaneous preterm birth (aOR: 1.28; 95% CI: 1.03, 1.58; p = 0.024), congenital anomalies (aOR: 1.69; 95% CI: 1.15, 2.50; p = 0.008), and maternal intensive care unit admission at delivery (aOR: 7.44; 95% CI: 4.06, 13.62; p < 0.001) but not preeclampsia/eclampsia (aOR: 1.14; 95% CI: 0.98, 1.33; p = 0.080). Eighteen (0.8%) neonates of mothers who tested positive also had a positive SARS-CoV-2 test after 24 hours of birth, but all were asymptomatic during the neonatal period. Conclusion These findings suggest that prenatal SARS-CoV-2 infection increases the odds of some adverse perinatal outcomes. The likelihood of vertical transmission from the mother to the fetus was low (0.3%), suggesting that pregnancy complications resulting from SARS-CoV-2 infection pose more risk to the baby than transplacental viral transmission. Key Points SARS-CoV-2 infection is associated with increased odds of adverse perinatal outcomes. The odds of specific adverse outcomes were greater when a mother was infected earlier in pregnancy. The proportion of vertical transmission from mother to fetus was 0.3% [ABSTRACT FROM AUTHOR]

In the Vaccine Safety Datalink (VSD), we previously reported no association between coronavirus disease 2019 (COVID-19) vaccination in early pregnancy and spontaneous abortion (SAB). The present study aims to understand how time since vaccine rollout or other methodological factors could affect results. Using a case-control design and generalized estimating equations, we estimated the odds ratios (ORs) of COVID-19 vaccination in the 28 days before a SAB or last date of the surveillance period (index date) in ongoing pregnancies and occurrence of SAB, across cumulative 4-week periods from December 2020 through June 2021. Using data from a single site, we evaluated alternative methodological approaches: increasing the exposure window to 42 days, modifying the index date from the last day to the midpoint of the surveillance period, and constructing a cohort design with a time-dependent exposure model. A protective effect (OR = 0.78, 95% confidence interval: 0.69, 0.89), observed with 3-cumulative periods ending March 8, 2021, was attenuated when surveillance extended to June 28, 2021 (OR = 1.02, 95% confidence interval: 0.96, 1.08). We observed a lower OR for a 42-day window compared with a 28-day window. The time-dependent model showed no association. Timing of the surveillance appears to be an important factor affecting the observed vaccine-SAB association. [ABSTRACT FROM AUTHOR]

Background As prenatal vaccinations continue to be given more frequently, it is important to assess long-term safety events. We investigated the association between prenatal influenza vaccination or infection and autism spectrum disorder (ASD) in offspring. Methods A retrospective cohort study of mother–child pairs with deliveries between 1 January 2011 and 31 December 2014 at Kaiser Permanente Southern California was performed. Children aged >1 year were followed through 31 December 2018. Maternal influenza vaccination or infection during pregnancy was obtained from electronic health records. ASD was defined by International Classification of Diseases, Ninth or Tenth Revisions, Clinical Modification , codes after age 1 year. Cox proportional hazard models estimated the crude and inverse probability of treatment weighted (IPTW) hazard ratios (HR) for the association between maternal influenza vaccination or infection and ASD. Results There were 84 739 mother–child pairs included in the final analytic sample. Of the 46 257 women vaccinated, 32.4% were vaccinated during the first trimester, 41.8% during the second trimester, and 25.8% during the third trimester. ASD was diagnosed in 1930 (2.3%) children. The IPTW analyses showed no association between prenatal influenza vaccination or infection and ASD in offspring (HR, 1.04; 95% confidence interval [CI],.95–1.13; HR, 1.12; 95% CI,.66–1.89, respectively). Conclusions Prenatal influenza vaccination or infection was not associated with ASD risk in offspring. The findings support recommendations to vaccinate pregnant women to protect themselves and their infants, both of whom are vulnerable to severe morbidity following infection. [ABSTRACT FROM AUTHOR]

Background Intrapartum antibiotic prophylaxis (IAP) reduces a newborn's risk of group B streptococcal infection (GBS) but may lead to an increased childhood body mass index (BMI). Methods This was a retrospective cohort study of infants (n = 223 431) born 2007–2015 in an integrated healthcare system. For vaginal delivery, we compared children exposed to GBS-IAP and to any other type or duration of intrapartum antibiotics to no antibiotic exposure. For cesarean delivery, we compared children exposed to GBS-IAP to those exposed to all other intrapartum antibiotics, including surgical prophylaxis. BMI over 5 years was compared using nonlinear multivariate models with B-spline functions, stratified by delivery mode and adjusted for demographics, maternal factors, breastfeeding, and childhood antibiotic exposure. Results In vaginal deliveries, GBS-IAP was associated with higher BMI from 0.5 to 5.0 years of age compared to no antibiotics (P  < .0001 for all time points, ΔBMI at age 5 years 0.12 kg/m2, 95% confidence interval [CI]:.07–.16 kg/m2). Other antibiotics were associated with higher BMI from 0.3 to 5.0 years of age. In cesarean deliveries, GBS-IAP was associated with increased BMI from 0.7 years to 5.0 years of age (P  < .05 for 0.7–0.8 years, P  < .0001 for all other time points) compared to other antibiotics (ΔBMI at age 5 years 0.24 kg/m2, 95% CI:.14–.34 kg/m2). Breastfeeding did not modify these associations. Conclusions GBS-IAP was associated with a small but sustained increase in BMI starting at very early age. This association highlights the need to better understand the effects of perinatal antibiotic exposure on childhood health. [ABSTRACT FROM AUTHOR]

Objective  This study aimed to determine if hypothyroidism prior to, or during, pregnancy increases the risk of attention-deficit hyperactivity disorder (ADHD) in the child and how the association may be modified by preterm birth, sex of the child, and race-ethnicity. Study Design  Data were abstracted from linked maternal–child medical records. Incidence rate differences (IRDs), adjusted hazard ratios (aHRs), and their 95% confidence intervals (CIs) were estimated to evaluate the association of maternal hypothyroidism with childhood ADHD risk. Stratified analyses were used to evaluate whether the association is affected by timing of first diagnosis, gestational age at birth (term vs. preterm), sex, and race-ethnicity. Results  Hypothyroidism diagnosed prior to (IRD = 1.30), or during (IRD = 0.59) pregnancy increases the risk of ADHD in the children (aHR = 1.27; 95% CI: 1.15, 1.41, and 1.17; 95% CI: 1.00, 1.38). The association was strongest when diagnosed during the first trimester (IRD = 0.97 and aHR = 1.28; 95% CI: 1.04, 1.58). For children born preterm, there was significantly increased risk of ADHD if their mothers were diagnosed prior to (IRD = 3.06 and aHR = 1.43; 95% CI: 1.09, 1.88), but not during pregnancy. The effect of maternal hypothyroidism on increased risk of ADHD was stronger for boys (IRD = 1.84 and aHR = 1.26; 95% CI: 1.14, 1.40) than it was for girls (IRD = 0.48 and aHR = 1.19; 95% CI: 1.01, 1.40) and for Hispanic children (IRD = 1.60 and aHR = 1.45; 95% CI: 1.25, 1.68) compared with other race ethnicities. Conclusion  Exposure to maternal hypothyroidism during the periconceptual period significantly increases the risk of ADHD and that the association varies with gestational age at delivery, child sex, and race-ethnicity. Key Points Maternal hypothyroidism increases the risk of ADHD diagnosis in the offspring. The association of maternal hypothyroidism with childhood ADHD was influenced by timing of diagnosis. Strength of the association was strongest in preterm born infants, boys, and Hispanic children. [ABSTRACT FROM AUTHOR]

Objective  The coronavirus disease 2019 (COVID-19) pandemic has created a need for data regarding the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in pregnant women. After implementing universal screening for COVID-19 in women admitted for delivery, we sought to describe the characteristics of COVID-19 in this large cohort of women. Study Design  An observational study of women admitted to labor and delivery units in Kaiser Permanente Southern California (KPSC) hospitals between April 6 and May 11, 2020 who were universally offered testing for SARS-CoV-2 infection (n  = 3,963). Hospital inpatient and outpatient physician encounter, and laboratory records were used to ascertain universal testing levels, test results, and medical and obstetrical histories. The prevalence of SARS-CoV-2 infection was estimated from the number of women who tested positive during labor per 100 women delivered. Results  Of women delivered during the study period, 3,923 (99.0%) underwent SARS-CoV-2 testing. A total of 17 (0.43%; 95% confidence interval: 0.23–0.63%) women tested positive, and none of them were symptomatic on admission. There was no difference in terms of characteristics between SARS-CoV-2 positive and negative tested women. One woman developed a headache attributed to COVID-19 3 days postpartum. No neonates had a positive test at 24 hours of life. Conclusion  The findings suggest that in pregnant women admitted for delivery between April 6 and May 11, 2020 in this large integrated health care system in Southern California, prevalence of SARS-CoV-2 test positive was very low and all patients were asymptomatic on admission. Key Points The prevalence of SARS-CoV-2 infection in a large diverse cohort of term pregnant women was 0.43%. 99% of women accepted SARS-CoV-2 screening on admission to labor and delivery. All women with positive test results were asymptomatic at the time of testing. [ABSTRACT FROM AUTHOR]

Prenatal clinical notes in electronic medical records contain a wealth of information on pregnancy complications and outcomes. Extracting this critical information provides a unique opportunity for risk assessment to identify at-risk patients who may benefit from early monitoring and intervention. We developed and validated a rule-based computerized algorithm called PregHisEx to characterize past obstetrical history (preeclampsia/eclampsia) by mining prenatal clinical notes for women delivered in 2012 within a large healthcare maintenance organization. The algorithm successfully identified cases with past history of preeclampsia/eclampsia: 2984 definite and 479 probable cases at sentence level; 2419 definite and 348 probable cases at note level; and 762 definite and 82 probable cases at pregnancy episode level. Validation conducted on a random sample of 200 notes using PregHisEx yielded 88.0 percent sensitivity, 98.9 percent specificity, 91.7 percent positive predictive value, 98.3 percent negative predictive value, and F-score of 0.90. The high-performing PregHisEx can be applied for other prenatal conditions. [ABSTRACT FROM AUTHOR]

Objective: Tributyltin (TBT) is a persistent pollutant but its effects on placental function are poorly understood as are its possible interactions with infection. We hypothesized that TBT alters the production of sex hormones and biomarkers for inflammation and neurodevelopment in an infection-dependent manner. Methods: Placental explant cultures were treated with 0–5000 nM TBT in the presence and absence of Escherichia coli. A conditioned medium was harvested and concentrations of steroids (progesterone, P4; testosterone, T and estradiol, E2) as well as biomarkers of inflammation [interleukin (IL)-1β (IL-1β), tumor necrosis factor (TNF-α), IL-10, IL-6, soluble glycoprotein 130 (sgp-130) and heme oxygenase-1 (HO-1)], oxidative stress [8-iso-prostaglandin (8-IsoP)] and neurodevelopment [brain-derived neurotrophic factor (BDNF)] were quantified. Results: TBT increased P4 slightly but had little or no effect on T or E2 production. IL-1β, IL-6, sgp-130, IL-10 and 8-IsoP production was enhanced by TBT. P4 and IL-6 production was also enhanced by TBT for bacteria-stimulated cultures but TBT significantly inhibited bacteria-induced IL-1β and sgp-130 production. High doses of TBT also inhibited BDNF production. Conclusions: TBT increases P4 but has minimal effect on downstream steroids. It enhances the production of inflammatory biomarkers such as IL-1β, TNF-α, IL-10 and IL-6. Inhibition of sgp-130 by TBT suggests that TBT may increase bioactive IL-6 production which has been associated with adverse neurodevelopmental outcomes. Reduced expression of BDNF also supports this possibility. [ABSTRACT FROM AUTHOR]

Objective To examine the association between exposures to perinatal factors and autism spectrum disorders (ASD). Study Design A retrospective cohort study of ASD among children born in Kaiser Permanente Southern California hospitals between 1991 and 2009 (n = 594,638). Medical records were used to determine exposure to perinatal (antepartum and intrapartum) complications. ASD was diagnosed using DSM-IV criteria. Multivariable Cox regression was used to estimate hazard ratios (HRs). Result Children with ASD were more likely to be exposed to perinatal complications (HR = 1.15, 95% confidence interval [CI]: 1.09-1.21) than neurotypical children. Children exposed to antepartum (HR = 1.22, 95% CI: 1.10-1.36) and intrapartum (HR = 1.10, 95% CI: 1.04-1.17) complications were at increased risk of ASD. The risk was even greater when both antepartum and intrapartum conditions were present (HR = 1.44, 95% CI: 1.26-1.63). Conclusion Exposure to antepartum or intrapartum complications increases the risk of ASD in the offspring. Therefore, pregnancy complications may help identify children who could benefit from early screening and intervention for this common neuro-developmental condition. [ABSTRACT FROM AUTHOR]

IMPORTANCE Information about the association of maternal diabetes and autism spectrum disorders (ASDs) in offspring is limited, with no report on the importance of timing of exposure during gestation. OBJECTIVE To assess ASD risk associated with intrauterine exposure to preexisting type 2 diabetes and gestational diabetes mellitus (GDM) by gestational age at GDM diagnosis. DESIGN, SETTING, AND PATIENTS Retrospective longitudinal cohort study including 322 323 singleton children born in 1995-2009 at Kaiser Permanente Southern California (KPSC) hospitals. Children were tracked from birth until the first of the following: date of clinical diagnosis of ASD, last date of continuous KPSC health plan membership, death due to any cause, or December 31, 2012. Relative risks of ASD were estimated by hazard ratios (HRs) using Cox regression models adjusted for birth year. EXPOSURES Maternal preexisting type 2 diabetes (n = 6496), GDM diagnosed at 26 weeks’ gestation or earlier (n = 7456) or after 26 weeks’ gestation (n = 17 579), or no diabetes (n = 290 792) during the index pregnancy. MAIN OUTCOMES AND MEASURES Clinical diagnosis of ASD in offspring. RESULTS During follow-up, 3388 children were diagnosed as having ASD (115 exposed to preexisting type 2 diabetes, 130 exposed to GDM at ≤26 weeks, 180 exposed to GDM at >26 weeks, and 2963 unexposed). Unadjusted annual ASD incidences were 3.26, 3.02, 1.77, and 1.77 per 1000 among children of mothers with preexisting type 2 diabetes, GDM diagnosed at 26 weeks or earlier, GDM diagnosed after 26 weeks, and no diabetes, respectively. The birth year–adjusted HRs were 1.59 (95% CI, 1.29-1.95) for preexisting type 2 diabetes, 1.63 (95% CI, 1.35-1.97) for GDM diagnosed at 26 weeks or earlier, and 0.98 (95% CI, 0.84-1.15) for GDM diagnosed after 26 weeks relative to no exposure. After adjustment for maternal age, parity, education, household income, race/ethnicity, history of comorbidity, and sex of the child, maternal preexisting type 2 diabetes was not significantly associated with risk of ASD in offspring (HR, 1.21; 95% CI, 0.97-1.52), but GDM diagnosed at 26 weeks or earlier remained so (HR, 1.42; 95% CI, 1.15-1.74). Antidiabetic medication exposure was not independently associated with ASD risk. Adjustment for a mother or older sibling with ASD in the full cohort and for maternal smoking, prepregnancy body mass index, and gestational weight gain in the subset with available data (n = 68 512) did not affect the results. CONCLUSIONS AND RELEVANCE In this large, multiethnic clinical cohort of singleton children born at 28 to 44 weeks’ gestation, exposure to maternal GDM diagnosed by 26 weeks’ gestation was associated with risk of ASD in offspring. [ABSTRACT FROM AUTHOR]

ABSTRACT Purpose To evaluate the validity of health plan and birth certificate data for pregnancy research. Methods A retrospective study was conducted using administrative and claims data from 11 U.S. health plans and corresponding birth certificate data from state health departments. Diagnoses, drug dispensings, and procedure codes were used to identify infant outcomes (cardiac defects, anencephaly, preterm birth, and neonatal intensive care unit [NICU] admission) and maternal diagnoses (asthma and systemic lupus erythematosus [SLE]) recorded in the health plan data for live born deliveries between January 2001 and December 2007. A random sample of medical charts ( n = 802) was abstracted for infants and mothers identified with the specified outcomes. Information on newborn, maternal, and paternal characteristics (gestational age at birth, birth weight, previous pregnancies and live births, race/ethnicity) was also abstracted and compared to birth certificate data. Positive predictive values (PPVs) were calculated with documentation in the medical chart serving as the gold standard. Results PPVs were 71% for cardiac defects, 37% for anencephaly, 87% for preterm birth, and 92% for NICU admission. PPVs for algorithms to identify maternal diagnoses of asthma and SLE were ≥ 93%. Our findings indicated considerable agreement (PPVs > 90%) between birth certificate and medical record data for measures related to birth weight, gestational age, prior obstetrical history, and race/ethnicity. Conclusions Health plan and birth certificate data can be useful to accurately identify some infant outcomes, maternal diagnoses, and newborn, maternal, and paternal characteristics. Other outcomes and variables may require medical record review for validation. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Objective. Patterns of recurrence of restricted fetal growth provide important insights to understand the relative contributions of genetic versus environmental influences. Although there is evidence of increased tendency of small for gestational age (SGA) births to recur, whether similar patterns of recurrence in twins among women that delivered a prior singleton SGA birth remains poorly studied. Methods. We used Missouri's maternally-linked data (1978-1997), and restricted the analysis to women that delivered their first two consecutive live births. SGA (birthweight <10th and <5th centile for gestational age) recurrence was examined in two distinct analyses: women that delivered their first two singleton live births (n = 305,654) and those that delivered their first singleton live birth followed by twin live births (n = 8594). Sib-sib pairwise odds ratio (pOR) were estimated from bivariate logistic regression with robust variance estimation after adjustments for confounders. Results. Risks of SGA were 24.3% and 6.1% in the second singleton birth among women with and without a previous singleton SGA, respectively (pOR 3.9, 95% CI 3.7-4.0). The corresponding risks among twins with and without a previous singleton SGA birth were 16.9% and 6.7%, respectively (pOR 2.3, 95% CI 1.8-2.8). In the singleton-singleton cohort, the highest recurrence risk for SGA occurred around the same gestational age window as the first singleton SGA birth. These associations were stronger for more severe forms of SGA (<5th centile). Conclusions. The likelihood of SGA to recur within sibships is strong, with varying magnitude of risks between singleton-singleton and singleton-twin births. [ABSTRACT FROM AUTHOR]

Objective. To examine whether acute and chronic respiratory diseases are associated with an increased risk of spontaneous premature rupture of the membranes (PROM). Methods. We used the 1993-2004 National Hospital Discharge Survey data of singleton deliveries in the USA (N = 41 250 539). The International Classification of Diseases Ninth Revision was utilized to identify acute (acute upper respiratory diseases, viral/bacterial pneumonia, and acute bronchitis/bronchiolitis) and chronic (chronic bronchitis and asthma) respiratory conditions and spontaneous PROM. All analyses were adjusted for potential confounders. Results. The incidence of PROM was 5%, and rates of acute and chronic respiratory conditions were 2.1 and 9.5 per 1000 pregnancies, respectively. Chronic bronchitis was associated with a reduced risk of PROM (RR 0.39, 95% CI 0.31, 0.48). Asthma was significantly associated with PROM at preterm (RR 1.15, 95% CI 1.14, 1.17) and term (RR 1.27, 95% CI 1.23, 1.30). Stratification by race showed that acute upper respiratory disease was associated with preterm PROM in whites (RR 1.90, 95% CI 1.71, 2.11) and blacks (RR 6.76, 95% CI 5.67, 8.07). Viral/bacterial pneumonia was associated with preterm PROM in blacks and term PROM in both races. Asthma was associated with term PROM in blacks but not whites. Conclusions. Acute respiratory diseases and asthma during pregnancy are associated with spontaneous PROM, with substantially stronger association among blacks than whites. We speculate that timely diagnosis and treatment, coupled with closely mentoring of pregnant women may help reduce the rate of PROM and associated complications. [ABSTRACT FROM AUTHOR]

Objective. Most women in their first pregnancy are at 'unknown' risk for preterm birth. We hypothesized that such women may be at an increased risk for preterm birth in comparison to those with a prior term birth. Methods. We used Missouri's maternally-linked data (1989-97), comprised of women delivering their first singleton live birth (N = 259 431) and women delivering their first two consecutive singleton live births (N = 154 810). We compared preterm birth (<37 weeks) rates among women with a previous term birth, women with no reproductive history (primiparous women), and in those with a previous preterm birth. Risks of spontaneous and medically indicated preterm birth were also examined after adjustments for confounders through multivariate log-binomial regression models. Results. Preterm birth rates were 8.1%, 9.6%, and 23.3% among women with a previous term birth, among primiparous women, and among those with a previous preterm birth, respectively. In comparison to women with a prior term birth, risks of spontaneous preterm birth among primiparous women and among women with a prior preterm birth were 1.1-fold (95% confidence interval (CI) 1.0, 1.2) and 2.5-fold (95% CI 2.4, 2.6) higher, respectively. These risks were higher for medically indicated preterm birth among both primiparous women (RR 1.3, 95% CI 1.2, 1.4) and those with a prior preterm birth (RR 3.2, 95% CI 3.0, 3.5) than for spontaneous preterm births. Conclusions. Primiparous women are at increased risk of both medically indicated and spontaneous preterm birth. The findings suggest that studies on preterm birth should consider a risk assignment to include three groups: low-risk (prior term birth), intermediate risk (primiparity), and high-risk (prior preterm birth). This strategy will be informative for the identification of women with impending risk of delivering preterm, and complications associated with prematurity. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to examine temporal changes in stillbirth, neonatal and infant mortality rates among triplet births in the US, and to assess the contributions of triplet delivery at <34 weeks to these changes. Study design: Data on triplet live births, and fetal and infant deaths (1990-2002) delivered at ≥=22 weeks and fetuses weighing ≥=500 g (n = 66,986) were derived from the US linked birth/infant death data files. Relative risk (RR), quantifying changes in triplet stillbirth, neonatal (death within the first 28 days) and infant mortality (death within the first year) rates between 1990 and 1991 and 2001 and 2002, were derived. Temporal changes in triplet births at <34 weeks, and changes in still- birth, and neonatal and infant mortality rates were examined through logistic regression models before and after adjusting for confounders. Results: Triplet births at <34 weeks increased by 25% between 1990 and 1991 (48.7%) and 2001 and 2002 (60.9%). Stillbirth, neonatal and infant mortality rates declined by 52% (RR 0.48, 95% confidence interval [CI] 0.36-0.63), 32% (RR 0.68, 95% CI 0.58-0.80), and 38% (RR 0.62, 95% CI 0.53-0.71), respectively, between 1990 and 1991 and 2001 and 2002. The increase in triplet births at <34 weeks was not associated with the stillbirth decline, but was associated with an excess 14% and 12% increase in neonatal and infant deaths, respectively. Conclusion: Our findings suggest that the increase in triplet births at <34 weeks' gestation is not associated with changes in triplet stillbirths, but is associated with increases in triplet neonatal and infant mortality. [ABSTRACT FROM AUTHOR]

Objective: This study was undertaken to examine the associations between maternal respiratory diseases and placental abruption. Study design: A population-based, retrospective cohort study was conducted to examine the associations between maternal respiratory diseases and abruption in the United States. Data on women who delivered singleton births (n = 37,314,022) were derived from the National Hospital Discharge Survey for the years 1993 to 2003. International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes were used to identify pregnant women hospitalized for acute upper respiratory diseases, viral and bacterial pneumonia, acute bronchitis, and acute bronchiolitis, chronic bronchitis, asthma, and abruption. Relative risk (RR) and 95% CI were derived from multivariable logistic regression models to evaluate the associations after adjusting for maternal age, race, marital status, smoking, cocaine use, adequacy of prenatal care, maternal insurance status, geographic location, and year of birth (although data on smoking and cocaine use are likely underreported). Results: The rate of abruption was 9.7 per 1,000 singleton births. The overall rate for acute respiratory conditions was 2.2 per 1000 pregnancies. Acute upper respiratory diseases (RR 3.2, 95% CI 3.0-3.4) and viral/bacterial pneumonia (RR 2.2, 95% CI 1.9–2.4) were associated with abruption. The rate of chronic respiratory conditions was 9.0 per 1,000 pregnancies. Chronic bronchitis was strongly associated with abruption (RR 31.8, 95% CI 29.6–34.3), but the association between asthma and abruption was modest (RR 1.1, 95% CI 1.0–1.2). Stratified analysis by maternal race showed that asthma was associated with abruption among black women but not white women. Conclusion: Pregnancies complicated by acute and chronic respiratory diseases requiring hospitalization are associated with placental abruption. [ABSTRACT FROM AUTHOR]

The article investigates the magnitude of associations of acute and chronic processes with placental abruptions in preterm and term gestations. Results reveal that among women with placental abruption, conditions associated with acute inflammation are more prevalent at preterm than term gestations, while chronic processes are present throughout gestation.

Background: Several studies have assessed the risks of uteroplacental bleeding disorders in relation to maternal characteristics. The association between uteroplacental bleeding disorders and paternal characteristics, however, has received considerably less attention. Data on paternal demographics, notably race and age, from birth certificate data are becoming increasingly incomplete in recent years. This pattern of increasingly underreporting of paternal demographic data led us to speculate that pregnancies for which paternal characteristics are partially or completely missing may be associated with increased risk for uteroplacental bleeding disorders. The objective of this study is to examine the association between placenta previa and placental abruption and missing paternal age and race. Methods: A retrospective cohort study using U.S. linked birth/infant death data from 1995 through 2001 (n = 26,336,549) was performed. Risks of placenta previa and placental abruption among: (i) pregnancies with complete paternal age and race data; (ii) paternal age only missing; (iii) paternal race only missing; and (iv) both paternal age and race missing, were evaluated. Relative risk (RR) with 95% confidence interval (CI) for placenta previa and placental abruption by missing paternal characteristics were derived after adjusting for confounders. Results: Adjusted RR for placental abruption were 1.30 (95% CI 1.24, 1.37), 1.00 (95% CI 0.95, 1.05), and 1.08 (95% CI 1.06, 1.10) among pregnancies with "paternal age only", "paternal race only", and "both paternal age and race" missing, respectively. The increased risk of placental abruption among the "paternal age only missing" category is partly explained by increased risks among whites aged 20-29 years, and among blacks aged ⩾30 years. However, no clear patterns in the associations between missing paternal characteristics and placenta previa were evident. Conclusion: Missing paternal characteristics are associated with increased risk of placental abruption, likely mediated through low socio-economic conditions. [ABSTRACT FROM AUTHOR]

Objective: We examined the association between parental race and stillbirth and adverse perinatal and infant outcomes. Methods: We conducted a retrospective cohort analysis using the 1995–2001 linked birth and infant death files that are composed of live births and fetal and infant deaths in the United States. The study included singleton births delivered at 20 or more weeks of gestation with a fetus weighing 500 g or more (N = 21,005,786). Parental race was categorized as mother white-father white, mother white-father black, mother black-father white, and mother black-father black. Multivariable logistic regression analysis was performed to examine the association between parental race and risks of stillbirth (at ≥ 20 weeks), small for gestational age (defined as birth weight « 5th and « 10th percentile for gestational age), and early neonatal (« 7 days), late neonatal (7–27 days), and postneonatal (28–364 days) mortality. All analyses were adjusted for the confounding effects of maternal age, education, trimester at which prenatal care began, parity, marital status, and smoking during pregnancy. Results: Although risks varied across parental race categories, stillbirth was associated with a higher-than-expected risk for interracial couples: mother white-father black, relative risk (RR) 1.17 (95% confidence interval [CI] 1.10–1.26) and mother black-father white, RR 1.37 (95% CI 1.21–1.54) compared with mother white-father white parents. The RR for stillbirth was even higher among mother black-father black parents (RR 1.67, 95% CI 1.62–1.72). The overall patterns of association for small for gestational age births (« 5th and « 10th percentile) and early neonatal mortality were similar to those seen for stillbirth. Conclusion: There is an increased risk of adverse perinatal outcomes for interracial couples, including stillbirth, small for gestational age infants, and neonatal mortality. [ABSTRACT FROM AUTHOR]

Objective: We sought to describe the incidence of acute pyelonephritis in pregnancy, and to assess its association with perinatal outcomes in an integrated health care system. Study Design: A retrospective cohort study was performed using medical records on 546,092 singleton pregnancies delivered in all Kaiser Permanente Southern California hospitals from 1993 through 2010. These medical records include the perinatal service system along with inpatient and outpatient encounter files. Adjusted odd ratios (ORs) and 95% confidence intervals (CIs) were used to estimate associations. Results: The incidence of acute antepartum pyelonephritis was 0.5% (2894/543,430). Women with pyelonephritis in pregnancy were more likely to be black or Hispanic, young, less educated, nulliparous, initiate prenatal care late, and smoke during pregnancy. Pregnancies of women with pyelonephritis compared to those without were more likely to be complicated by anemia (26.3% vs 11.4%; OR, 2.6; 95% CI, 2.4–2.9), septicemia (1.9% vs 0.03%; OR, 56.5; 95% CI, 41.3–77.4), acute pulmonary insufficiency (0.5% vs 0.04%; OR, 12.5; 95% CI, 7.2–21.6), acute renal dysfunction (0.4% vs 0.03%; OR, 16.5; 95% CI, 8.8–30.7), and spontaneous preterm birth (10.3% vs 7.9%; OR, 1.3; 95% CI, 1.2–1.5). Most of the preterm births occurred between 33-36 weeks (9.1%). Conclusion: We characterize the incidence of pyelonephritis in an integrated health care system where routine prenatal screening for asymptomatic bacteriuria is employed. Maternal complications are commonly encountered and the risk of preterm birth is higher than the baseline obstetric population. [ABSTRACT FROM AUTHOR]

To examine whether demographic and cancer-related characteristics and factors such as fertility discussion with a medical provider and fertility preservation use are associated with attempting pregnancy after adolescent and young adult cancer. Cross-sectional online survey. Not applicable. Women with lymphoma, breast cancer, thyroid cancer, or gynecologic cancer diagnosed at 15–39 years from 2004 to 2016 were identified from the North Carolina Cancer Registry and the Kaiser Permanente Northern and Southern California health care systems and responded to an online survey addressing survivorship concerns, including fertility and reproductive outcomes. Demographic characteristics, cancer characteristics, fertility discussion with a medical provider or fertility specialist between cancer diagnosis and starting cancer treatment, use of fertility preservation strategies (freezing embryos or oocytes) after cancer diagnosis. Pregnancy attempt after cancer diagnosis, defined by either a pregnancy or 12 months of trying to become pregnant without pregnancy. Among 801 participants who had not reached their desired family size at diagnosis, 77% had a fertility discussion with any medical provider between cancer diagnosis and treatment initiation, and 8% used fertility preservation after cancer diagnosis. At survey (median =7 years after diagnosis; interquartile range, 4–10), 32% had attempted pregnancy. Neither fertility discussion with any medical provider nor fertility counseling with a fertility specialist was significantly associated with pregnancy attempts. However, the use of fertility preservation was significantly associated with attempting pregnancy (prevalence ratios = 1.74; 95% confidence interval: 1.31–2.32). Other characteristics positively associated with pregnancy attempts included younger age at diagnosis, longer time since diagnosis, having a partner (at diagnosis or at survey), and having a history of infertility before cancer diagnosis. Use of fertility preservation strategies was uncommon in our cohort but was associated with attempting pregnancy after cancer. Ensuring access to fertility preservation methods may help adolescent and young adult cancer survivors to plan and initiate future fertility. [ABSTRACT FROM AUTHOR]

Objective: Heritable thrombophilias have been implicated as a potential cause of abruption by vascular disruption at the uteroplacental interface. Polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene have been linked to vascular complications outside of pregnancy, which includes stroke. Given the underlying thrombotic nature of abruption, we hypothesized that polymorphisms in the MTHFR gene are associated with abruption. Study Design: We examined 2 variants in MTHFR: 677C→T and 1298A→C in genomic DNA extracted from maternal blood from the New Jersey–Placental Abruption Study, an ongoing, multicenter case-controlled study. We identified 195 women with a clinical diagnosis of abruption (cases) and 189 control subjects who were matched on race/ethnicity and parity. We assessed allele and genotype frequencies and their associations with abruption risk after adjusting for confounders through multivariable logistic regression analysis. Results: The wild-type allele (C) frequency of the 677C→T variant of MTHFR among cases and control subjects was 69.0% and 64.3%, respectively; the wild-type allele (A) of the 1298A→C variant was 75.9% and 79.4%, respectively. Distributions of the 677C→T alleles among control subjects violated the Hardy–Weinberg equilibrium (P = .007); distributions of the 1298A→C alleles were in equilibrium (P = .825). In comparison to the wild-type genotype (C/C), the homozygous mutant form (T/T) of 677C→T was not associated with abruption (odds ratio, 0.60; 95% confidence interval [CI], 0.33-1.18). Similarly, the homozygous mutant form (C/C) of the 1298A→C polymorphism was distributed equally between cases and control subjects (odds ratio, 2.28; 95% CI, 0.82-6.35). Plasma homocysteine and vitamin B12, but not folate, concentrations were elevated in cases compared with control subjects among women with the wild-type genotype of MTHFR 677C→T (P = .039 for homocysteine; P = .048 for B12; P = .224 for folate). Conclusion: In this population, neither heterozygosity nor homozygosity for the 677C→T and 1298A→C variants in MTHFR was associated with placental abruption. [Copyright &y& Elsevier]

Objective: The objective of the study was to examine whether the risk and indications for primary cesarean in the second pregnancy are influenced by changes in prepregnancy body mass index (BMI) between pregnancies. Study Design: We performed a cohort analysis using the Missouri maternally linked birth and infant death surveillance datasets (1989-1997), comprised of women with their first 2 consecutive live births (n = 113,789). BMI (kilograms per square meter) was categorized as underweight (less than 18.5 kg/m2), normal (18.5 to 24.9 kg/m2), overweight (25 to 29.9 kg/m2), and obese (30 kg/m2 or greater). Indications for primary cesarean were categorized as breech, dystocia, fetal distress, and others. Timing of primary cesarean was categorized as elective (prior to labor) and emergent (after initiation of labor). Adjusted odds ratio (OR) was used to quantify the associations between changes in prepregnancy BMI and indications for primary cesarean. Results: The rate of primary cesarean in the second pregnancy was 9.2%. Compared with women with normal BMI in their first 2 pregnancies, women who increased their BMI between pregnancies had increased risk of primary cesarean for all indications. Women who remained obese or overweight in both pregnancies were at increased risk of primary cesarean following breech (OR 1.28 and 1.13, respectively); dystocia (OR 1.94 and 1.41, respectively); fetal distress (OR 1.43 and 1.26, respectively); others (OR 3.17 and 1.63, respectively); and elective (OR 2.31 and 1.43, respectively) and emergent (OR 1.66 and 1.30, respectively) cesarean section. Women who lowered their BMI from obese to overweight or overweight to normal between pregnancies had risks of primary cesarean comparable with those with normal BMI in both pregnancies. Any increase in BMI from underweight to overweight or obese between the first 2 pregnancies was associated with increased risk of primary cesarean (OR 1.20 to 3.04) in the second pregnancy. Conclusion: Increases in prepregnancy BMI between first 2 pregnancies from normal to obese is associated with increased risk of indications for primary cesarean. The association between being overweight or obese or increases in prepregnancy BMI between pregnancies and primary cesarean in the second pregnancy suggests that counseling women with regard to their high BMI may be beneficial. [Copyright &y& Elsevier]

Infection with hepatitis A virus (HAV) during pregnancy, although uncommon, is associated with gestational complications and pre-term labor. Hepatitis A vaccine (HepA) is recommended for anyone at increased risk for contracting hepatitis A, including women at risk who are also pregnant. Limited data are available on the safety of maternal HepA vaccination. Assess the frequency of maternal HepA receipt and evaluate the potential association between maternal vaccination and pre-specified maternal and infant safety outcomes. A retrospective cohort of pregnancies in the Vaccine Safety Datalink (VSD) resulting in live births from 2004 through 2015 was included. Pregnancies with HepA exposure were compared to those with other vaccine exposures, and to those with no vaccine exposures. Risk factors for contracting hepatitis A were identified up to one-year prior to or during the pregnancy using ICD-9 codes. Maternal and fetal adverse events were evaluated according to maternal HepA exposure status. Adjusted odds ratio (OR) were used to describe the association. Among 666,233 pregnancies in the study period, HepA was administered at a rate of 1.7 per 1000 (n = 1140), most commonly within the first six weeks of pregnancy. Less than 3% of those exposed to HepA during pregnancy had an ICD-confirmed risk factor. There were no significant associations between HepA exposure during pregnancy and gestational hypertension, gestational diabetes, pre-eclampsia/eclampsia, cesarean delivery, pre-term delivery, and low birthweight. There was a statistically significant association between HepA exposure during pregnancy and small-for-gestational age (SGA) infants (aOR 1.32, [95% CI 1.09, 1.60], p = 0.004). The rate of maternal HepA vaccination was low and rarely due to documented risk factors for vaccination. HepA vaccination during pregnancy was not associated with an increased risk for a range of adverse events examined among pregnancies resulting in live births, but an identified association between maternal HepA and SGA infant outcomes, while likely due to unmeasured confounding, warrants further exploration. [ABSTRACT FROM AUTHOR]

Highlights • Maternal HepB vaccination is infrequent, with a rate of 2.1 per 1000 pregnancies. • Women had a low rate of high-risk conditions indicated for maternal vaccination. • Maternal HepB vaccination does not increase risk for adverse events. Abstract Introduction Hepatitis B virus (HBV) infection acquired during pregnancy can pose a risk to the infant at birth that can lead to significant and lifelong morbidity. Hepatitis B vaccine (HepB) is recommended for anyone at increased risk for contracting HBV infection, including pregnant women. Limited data are available on the safety of HepB administration during pregnancy. Objectives To assess the frequency of maternal HepB receipt among pregnant women and evaluate the potential association between maternal vaccination and pre-specified maternal and infant safety outcomes. Methods We examined a retrospective cohort of pregnancies in the Vaccine Safety Datalink (VSD) resulting in live birth outcomes from 2004 through 2015. Eligible pregnancies in women aged 12–55 years who were continuously enrolled from 6 months pre-pregnancy to 6 weeks postpartum in VSD integrated health systems were included. We compared pregnancies with HepB exposure to those with other vaccine exposures, and to those with no vaccine exposures. High-risk conditions for contracting HBV infection were identified up to one-year prior to or during the pregnancy using ICD-9 codes. Maternal and fetal adverse events were also evaluated according to maternal HepB exposure status. Results Among over 650,000 pregnancies in the study period, HepB was administered at a rate of 2.1 per 1000 pregnancies (n = 1399), commonly within the first 5 weeks of pregnancy. Less than 3% of the HepB-exposed group had a high-risk ICD-9 code indicating need for HepB; this was similar to the rate among HepB unvaccinated groups. There were no significant associations between HepB exposure during pregnancy and gestational hypertension, gestational diabetes, pre-eclampsia/eclampsia, cesarean delivery, pre-term delivery, low birthweight or small for gestational age infants. Conclusions Most women who received maternal HepB did not have high-risk indications for vaccination. No increased risk for the adverse events that were examined were observed among women who received maternal HepB or their offspring. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To test the association of elective induction of labor at term compared with expectant management and maternal and neonatal outcomes. METHODS: This was a retrospective cohort study of all deliveries without prior cesarean delivery in California in 2006 using linked hospital discharge and vital statistics data. We compared elective induction at each term gestational age (37-40 weeks) as defined by The Joint Commission with expectant management in vertex, nonanomalous, singleton deliveries. We used multivariable logistic regression to test the association of elective induction and cesarean delivery, operative vaginal delivery, maternal third- or fourth-degree lacerations, perinatal death, neonatal intensive care unit admission, respiratory distress, shoulder dystocia, hyperbilirubinemia, and macrosomia (birth weight greater than 4,000 g) at each gestational week, stratified by parity. RESULTS: The cesarean delivery rate was 16%, perinatal mortality was 0.2%, and neonatal intensive care unit admission was 6.2% (N=362,154). The odds of cesarean delivery were lower among women with elective induction compared with expectant management across all gestational ages and parity (37 weeks [odds ratio (OR) 0.44, 95% confidence interval (CI) 0.34-0.57], 38 weeks [OR 0.43, 95% CI 0.38-0.50], 39 weeks [OR 0.46, 95% CI 0.41-0.52], 40 weeks [OR 0.57, CI 0.50-0.65]). Elective induction was not associated with increased odds of severe lacerations, operative vaginal delivery, perinatal death, neonatal intensive care unit admission, respiratory distress, shoulder dystocia, or macrosomia at any term gestational age. Elective induction was associated with increased odds of hyperbilirubinemia at 37 and 38 weeks of gestation and shoulder dystocia at 39 weeks of gestation. CONCLUSION: Elective induction of labor is associated with decreased odds of cesarean delivery when compared with expectant management. [ABSTRACT FROM AUTHOR]

Abstract: Background: Clinicians widely regard placental abruption as an acute event, though accumulating data point towards abruption being the end-result of chronic processes early in pregnancy, and perhaps even extending to conception. The Collaborative Perinatal Project was a prospective cohort study performed from 1959 to 1966 in the United States. Since enrolled pregnancies were managed without the biases created by modern perinatal surveillance and interventions, the natural history of disease in these data is ideal to study obstetrical complications such as placental abruption. Objective: We assessed the associations versus contributions of the clinical feature of early gestational vaginal bleeding and histologic lesions (chronic and acute) with placental abruption. Study design: Women enrolled in the Collaborative Perinatal Project (1959–1966) were used, restricting the analysis to those that delivered singleton births (n =46,364). Risks of placental abruption were compared between women with and without vaginal bleeding at <20 weeks gestation. We also examined the relationships between placental abruption and chronic and acute histologic lesions, including infarcts, decidual necrosis, presence of macrophages in the decidua, amnion or chorion, and neutrophil infiltration in the amnion, chorion, placental surface, and umbilical vein. Results: Any episode of vaginal bleeding at <20 weeks in pregnancy conferred an increased risk of placental abruption (adjusted relative risk (RR) 1.6, 95% confidence interval (CI) 1.3, 1.8). The greatest risk occurred with bleeding in both the first two trimesters (RR 3.1, 95% CI 2.3, 4.1). The presence of histologic lesions in the placenta, cord and membranes similarly carried an increased risk of placental abruption, even in the absence of vaginal bleeding. The risk of abruption was, however, highest in the presence of both histologic lesions and vaginal bleeding early in pregnancy. Conclusion: Vaginal bleeding early in pregnancy and histologic lesions of the placenta, umbilical cord, and membranes are associated with increased risk of placental abruption in later pregnancy. However, the increased risk associated with placental lesions, especially chronic inflammatory lesions, even in the absence of early vaginal bleeding, suggests that prolonged inflammation may be implicated in placental abruption. [Copyright &y& Elsevier]