California Birth Research Articles

Immigrant apprehensions and birth outcomes: Evidence from California birth records 2008-2015.

While several studies find adverse birth outcomes among Latina mothers after discrete immigration enforcement events, it is unknown whether day-to-day enforcement activities precede adverse birth outcomes. This study examines birth outcomes among Latinas following local immigrant apprehensions-48-h holds on suspected undocumented immigrants by local law enforcement-over an 8-year period. County-level apprehensions, scaled to 1000 of the population, were averaged across the third trimester. We analyzed the association between county-level apprehensions and low birth weight (LBW) and preterm birth (PTB) between 2008 and 2015 in California using spline logistic regression models with knots at the quartiles of apprehensions and included covariates, county fixed-effects, and a time propensity variable to account for trend and seasonality in LBW and PTB. We performed these regressions for non-Hispanic White, all Latina, and foreign-born (FB) Latina mothers. There were no significant associations between apprehensions and LBW. For all Latina women, there were no differences in PTB between zero apprehensions and levels that were below the median. Latina mothers exposed to moderately high apprehensions had lower odds for PTB compared to zero apprehensions. At the highest levels of apprehensions, however, Latina women showed significantly elevated odds of PTB (at 0.71 apprehensions: OR=1.06, 95% CI 1.01-1.12). PTB responded differentially to localized enforcement threats. At lower and moderate levels, Latino communities may have mobilized in ways that reduced the risk for PTB. Risks emerged at the highest levels of enforcement, underlying the intense fear and anxiety in hyper-surveilled areas.

Mediation of Adverse Pregnancy Outcomes in Autoimmune Conditions by Pregnancy Complications: A Mediation Analysis of Autoimmune Conditions and Adverse Pregnancy Outcomes.

Autoimmune conditions are associated with an increased risk of adverse pregnancy complications and outcomes, suggesting that pregnancy complications may mediate the excess risk. We performed a causal mediation analysis to quantify the mediated effects of autoimmune conditions on adverse pregnancy outcomes. We queried a California birth cohort created from linked birth certificates and hospital discharge summaries. From 2,963,888 births, we identified women with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), psoriasis, and inflammatory bowel disease (IBD). Pregnancy complications included preeclampsia/hypertension, gestational diabetes mellitus, and infection in pregnancy. Adverse pregnancy outcomes were preterm birth, cesarean delivery, and small for gestational age. We performed a mediation analysis to estimate the total effects of each autoimmune condition and adverse pregnancy outcome and the indirect effects through pregnancy complications. All 4 autoimmune conditions were associated with preterm birth and cesarean delivery, and RA, SLE, and IBD were associated with offspring that were small for gestational age. The strongest mediator of RA, SLE, and psoriasis was preeclampsia/hypertension, accounting for 20-33% of the excess risk of preterm births and 10-19% of excess cesarean deliveries. Gestational diabetes mellitus and infections generally mediated <10% of excess adverse pregnancy outcomes. Of the 4 autoimmune conditions, selected pregnancy complications mediated the least number of adverse pregnancy outcomes among women with IBD. We found evidence that some excess risk of adverse pregnancy outcomes is mediated through pregnancy complications, particularly preeclampsia/hypertension. Quantifying excess risk and associated pathways provides insight into the underlying etiologies of adverse pregnancy outcomes and can inform intervention strategies.

Neonatal abstinence syndrome management in California birth hospitals: results of a statewide survey

ObjectiveAssess management of neonatal abstinence syndrome (NAS) in California hospitals to identify potential opportunities to expand the use of best practices.Study designWe fielded an internet-based survey of 37 questions to medical directors or nurse managers at 145 birth hospitals in California.ResultsSeventy-five participants (52%) responded. Most respondents reported having at least one written protocol for managing NAS, but gaps included protocols for pharmacologic management. Newer tools for assessing NAS severity were not commonly used. About half reported usually or always using nonpharmacologic strategies; there is scope for increasing breastfeeding when recommended, skin-to-skin care, and rooming-in.ConclusionsWe found systematic gaps in care for infants with NAS in a sample of California birth hospitals, as well as opportunities to spread best practices. Adoption of new approaches will vary across hospitals. A concerted statewide effort to facilitate such implementation has strong potential to increase access to evidence-based treatment for infants and mothers.

431: Predictors of neonatal and post-neonatal death among preterm infants born between 34-36 weeks’ gestation

To examine the maternal factors associated with neonatal and post-neonatal death among preterm infants born between 34-36 weeks’ gestation. We conducted a retrospective cohort study of women with singleton, non-anomalous births in California from 2007 to 2011. We included live births between 34-36 weeks’ gestation. We categorized infant death into neonatal and post-neonatal death; neonatal death was defined as death occurring between 0-27 days after birth and post-neonatal death was 28-365 days after birth. We evaluated the association between neonatal and post-neonatal death with a variety of maternal socioeconomic and health characteristics to determine if different characteristics are associated with each. We only included variables in the multivariable logistic regression model if they were significantly different in bivariate analysis and excluded variables if they were collinear with others. Analyses were considered significant if the p-value was < 0.05. There were 150,241 live births between 34-36 weeks’ gestation, with 154 (0.1%) neonatal deaths and 230 (0.15%) post-neonatal deaths. Obese pre-pregnancy BMI and low prenatal care attendance were significantly associated with neonatal death (Table 1). Alternatively, Black race, overweight and obese pre-pregnancy BMI, low prenatal care attendance and chronic hypertension were significantly associated with post-neonatal death, while attending some college was protective (Table 2). We found that there are multiple variables that are associated with infant death among preterm infants born between 34-36 weeks’ gestation; however, there are differences between the predictors of neonatal and post-neonatal death, suggesting targeted interventions should be utilized.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

432: A cost analysis of chronic hypertension in a California cohort of pregnant women

Hospital costs in the United States are variable, with data lacking on the association between hospital costs and maternal and neonatal outcomes. Our objective was to estimate maternal and neonatal hospital costs among women with chronic hypertension in pregnancy in a large cohort of pregnant women. We conducted a retrospective cohort study of women with singleton, non-anomalous births in California from 2007 to 2011. We included only women with gestational ages greater than 23 weeks. Hospital costs were estimated separately for women and neonates using hospital charges adjusted using a cost-to-charge ratio of 0.58. This cost included hospital cost for admission for delivery only. We estimated the differences in median cost (maternal and neonatal) between chronic hypertension compared with no chronic hypertension. We also estimated length of stay for women and neonates, and estimated the gestational age at delivery. Analyses were conducted utilizing Kruskal-Wallis equality-of-populations rank tests with a significance cutoff of 0.05. In a California cohort of 2,401,049 women, 29,748 (1.2%) had chronic hypertension. The median hospital cost was $3,467 higher among women with chronic hypertension when compared to women without chronic hypertension (Table 1, p< 0.001). Length-of-stays were significantly different for women and neonates, in addition to gestational age at delivery (Table 1, p< 0.001). Median hospital costs were significantly higher for women with chronic hypertension regardless of mode of delivery or gestational age at delivery (Table 2a, p< 0.001). While the hospital costs for maternal Intensive Care Unit (ICU) admission did not significantly differ, the hospital cost was significantly higher among women with severe maternal morbidity and neonatal ICU admission (Table 2b, p< 0.001). In this analysis, the cost of chronic hypertension was significantly greater as compared to no chronic hypertension in pregnancy. This analysis allows for a greater understanding of the hospital costs associated with chronic hypertension in pregnancy.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

255: Predictors of neonatal and post-neonatal death among term infants born between 37-40 weeks’ gestation

To examine the maternal factors associated with neonatal and post-neonatal death among term infants born between 37-40 weeks’ gestation. We conducted a retrospective cohort study of women with singleton, non-anomalous births in California from 2007 to 2011. We included live births between 37-40 weeks’ gestation. We evaluated neonatal and post-neonatal death separately; neonatal death was defined as death occurring between 0-27 days after birth and post-neonatal death was 28-365 days after birth. We evaluated the association between neonatal and post-neonatal death with a variety of maternal socioeconomic and health characteristics. We only included variables in the multivariable logistic regression model if they were significantly different in bivariate analysis and excluded variables if they were collinear with others. Analyses were considered significant if the p-value was < 0.05. Among 616,597 live births between 37-40 weeks’ gestation, there were 228 (0.04%) neonatal deaths and 536 (0.09%) post-neonatal deaths. We found that low prenatal care attendance, public insurance and chronic hypertension were significantly associated with neonatal death (Table 1). Alternatively, Black race, overweight and obese pre-pregnancy BMI, low prenatal care attendance, diabetes and maternal age < 20 were significantly associated with post-neonatal death, while attending some college was protective (Table 2). Among early-term and term infants born between 37-40 weeks’ gestation, we found that multiple variables are associated with infant death. Differences in the predictors of neonatal and post-neonatal death suggest different interventions may be warranted for each.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

369: Racial/ethnic disparities in management of periviable deliveries between 23-25 weeks’ gestation

Racial/ethnic disparities have been recognized and well described with respect to all areas of healthcare, including pregnancy. This study analyzes racial/ethnic differences in the management and outcomes of periviable deliveries between 23-25 week’s gestational age. We conducted a retrospective cohort study of 2,925 periviable births between the weeks of 23-25 gestational age recorded in the California Birth Registry to examine components of the management of these pregnancies and several neonatal outcomes by maternal race. Race was classified as White, Black, Hispanic, Asian/Pacific Islander, and Other. Management approaches included use of betamethasone and cesarean delivery and perinatal outcomes of interest included intrauterine fetal death, neonatal death, intraventricular hemorrhage, and necrotizing enterocolitis. Results were analyzed with chi-squared tests and a p-value of less than 0.05 was used to indicate statistical significance. In our cohort of 2,925 periviable deliveries, there were significant differences in cesarean delivery, antenatal corticosteroid treatment, intrauterine fetal death, and neonatal death across the five groups of races with a p-value less than 0.05. We found no significant differences across racial/ethnic groups for intraventricular hemorrhage and necrotizing enterocolitis. Our results suggest that management approaches to periviable pregnancies vary by race/ethnicity. The risk of stillbirth and neonatal death also varies by race/ethnicity between 23-25 weeks of gestation. Further research should explore whether these disparities are due to management differences or patient preferences. Clinicians should be aware of such differences to ensure that such disparities are not due to practice patterns.

Experiences with Prenatal and Postpartum Contraceptive Services among Women with a Preterm Birth.

Providing postpartum contraception can help to achieve recommended interpregnancy intervals (≥18months from birth to next pregnancy), decrease the risk of preterm birth, and thus improve maternal and infant health outcomes of future pregnancies. However, the experiences of women with preterm birth regarding contraceptive services have not been documented. We sought to better understand contraceptive counseling experiences and postpartum contraception of women with a preterm birth. We interviewed 35 women, ages 18-42years, with a recent preterm birth in California. The transcribed interviews were analyzed using ATLAS.ti v.8. Women had public (n=15), private (n=16), or no insurance (n=4) at the time of the interview. Women were mainly Latina (n=14), Caucasian (n=9), or African American (n=6); 15 women were foreign born. Women's experiences ranged from spontaneous preterm births to births with severe medical complications. We identified five themes that were associated with women's engagement in the contraceptive method choice and understanding of birth spacing: 1) timing and frequency of contraceptive counseling; 2) quality of patient-provider interaction and ability to follow up on questions; 3) women's personal experiences with contraceptive use and experiences of other women; 4) context in which contraceptive counseling was framed; and 5) system barriers to contraceptive use. Postpartum contraceptive counseling should address women's preterm birth experience, medical conditions, age, contraceptive preference, and childbearing plans. Having a preterm birth intensifies gaps in hospital and outpatient clinic coordination and provider-patient communication that can lead to use of less effective or no contraceptive methods and risk of early subsequent unplanned pregnancies.

Male-to-Female Ratios, Race/Ethnicity, and Spontaneous Preterm Birth among 11 Million California Infants.

An observed disparity in population-scale data are a larger number of males among preterm births (PTBs). We investigated spontaneous PTB risk among women of various race/ethnic groups in combination with infants' sex. This observational study was conducted in > 10 million California births (1991-2012) using birth certificates linked with maternal and infant hospital discharge data. Male-to-female ratios among term (37-42 weeks) infants exhibited the narrow ratio range 1.02 to 1.06 across race/ethnic groups. Such ratios among spontaneous PTBs were generally larger for all race/ethnic groups except non-Hispanic blacks. For blacks, ratios tended to be lower and similar to their term birth counterpart, 1.03. Hazard ratios adjusted for maternal age and education for non-Hispanic blacks were 0.99 (95% confidence interval [CI] 0.90-1.09), 1.01 (95% CI 0.95-1.08), 0.98 (95% CI 0.94-1.03), and 1.03 (95% CI 1.01-1.05), respectively, for gestational week groupings of 20 to 23, 24 to 27, 28 to 321, and 32 to 36. Hazard ratios for non-Hispanic whites for the same groupings were 1.08 (95% CI 0.98-1.18), 1.13 (95% CI 1.07-1.19), 1.21 (95% CI 1.17-1.25), and 1.18 (95% CI 1.17-1.19). Why male-to-female ratios are similar across gestational ages in blacks but substantially higher in other race/ethnic groups is theoretically considered relative to inflammation, stress, and other influences.

Hospitalization costs associated with bronchopulmonary dysplasia in the first year of life.

ObjectiveTo determine costs of hospitalization associated with bronchopulmonary dysplasia (BPD) during the first year in very low birth weight infants.Study designRetrospective cohort study of California births from 2008 to 2011 linking birth certificate, discharge records, and clinical data from California Perinatal Quality Care Collaborative. Inclusion: birth weight 401–1500 g, gestational age < 30 weeks, inborn or transferred within 2 days, alive at 36 weeks corrected, and without major congenital anomalies. Outcomes included cost and length of stay of initial hospitalization and rehospitalizations.ResultOut of 7998 eligible infants, 2696 (33.7%) developed BPD. Median hospitalization cost in the first year was $377,871 per infant with BPD compared with $175,836 per infant without BPD (adjusted cost ratio 1.54, 95% confidence interval (CI) 1.49–1.59). Infants with BPD also had longer length of stay and a higher likelihood of rehospitalization.ConclusionBPD is associated with substantial resource utilization. Prevention strategies could help conserve healthcare resources.

Newborn Antibiotic Exposures and Association With Proven Bloodstream Infection.

To estimate the percentage of hospital births receiving antibiotics before being discharged from the hospital and efficiency diagnosing proven bloodstream infection. We conducted a cross-sectional study of 326 845 live births in 2017, with a 69% sample of all California births involving 121 California hospitals with a NICU, of which 116 routinely served inborn neonates. Exposure included intravenous or intramuscular antibiotic administered anywhere in the hospital during inpatient stay associated with maternal delivery. The main outcomes were the percent of newborns with antibiotic exposure and counts of exposed newborns per proven bloodstream infection. Units of observation and analysis were the individual hospitals. Correlation analyses included infection rates, surgical case volume, NICU inborn admission rates, and mortality rates. The percent of newborns with antibiotic exposure varied from 1.6% to 42.5% (mean 8.5%; SD 6.3%; median 7.3%). Across hospitals, 11.4 to 335.7 infants received antibiotics per proven early-onset sepsis case (mean 95.1; SD 71.1; median 69.5), and 2 to 164 infants received antibiotics per proven late-onset sepsis case (mean 19.6; SD 24.0; median 12.2). The percent of newborns with antibiotic exposure correlated neither with proven bloodstream infection nor with the percent of patient-days entailing antibiotic exposure. The percent of newborns with antibiotic exposure varies widely and is unexplained by proven bloodstream infection. Identification of sepsis, particularly early onset, often is extremely inefficient. Knowledge of the numbers of newborns receiving antibiotics complements evaluations anchored in days of exposure because these are uncorrelated measures.

Preterm birth phenotypes in women with autoimmune rheumatic diseases: a population-based cohort study.

To investigate preterm birth (PTB) phenotypes in women with different autoimmune rheumatic diseases in a large population-based cohort. Retrospective cohort study. California, USA. All live singleton births in California between 2007 and 2011 were analysed. Patients with autoimmune disease at delivery were identified by International Classification of Diseases, Ninth Revision , Clinical Modification (ICD-9-CM), codes for systemic lupus erythematosus (SLE), systemic sclerosis (SSc), rheumatoid arthritis (RA), polymyositis/dermatomyositis (DM/PM), and juvenile idiopathic arthritis (JIA). Maternally linked hospital and birth certificate records of 2481516 deliveries were assessed (SLE n=2272, RA n=1501, SSc n=88, JIA n=187, DM/PM n=38). Multivariable Poisson regression models estimated the risk ratios (RRs) for different PTB phenotypes (relative to term deliveries) for each autoimmune disease compared with the general obstetric population, adjusting for maternal age, race/ethnicity, body mass index, smoking, education, payer, parity, and prenatal care. Preterm birth (PTB) was assessed overall (20-36weeks of gestation) and by subphenotype: preterm prelabour rupture of membranes (PPROM), spontaneous birth, or medically indicated PTB. The risk of PTB overall and for each phenotype was partitioned by gestational age: early (20-31weeks of gestation) and late (32-36weeks of gestation). Risks for PTB were elevated for each autoimmune disease evaluated: SLE (RR 3.27, 95%CI 3.01-3.56), RA (RR 2.04, 95%CI 1.79-2.33), SSc (RR 3.74, 95%CI 2.51-5.58), JIA (RR 2.23, 95%CI 1.54-3.23), and DM/PM (RR 5.26, 95%CI 3.12-8.89). These elevated risks were observed for the majority of PTB phenotypes as well. Women with systemic autoimmune diseases appear to have an elevated risk of various PTB phenotypes. Therefore, preconception counselling and close monitoring during pregnancy is crucial. This study found that women with systemic autoimmune diseases have an elevated risk of preterm birth phenotypes.

1715. Coccidioidomycosis Outcomes Among Hospitalized Pregnant and Postpartum Women—California, 2000–2016

BackgroundCoccidioidomycosis (CM) in pregnancy has been associated with severe, disseminated disease. Publications are largely limited to case reports. Using California administrative hospital and birth registry data, we describe maternal and neonatal outcomes among pregnant and post-partum women hospitalized with CM.MethodsWe extracted California records from 2000 to 2016 for women 14–45 years, hospitalized with CM discharge codes; and used the birth registry to identify women who were pregnant or post-partum (≤30 days of childbirth) during their hospitalization. We used chi-squared tests to compare pregnant/post-partum women hospitalized with CM to nonpregnant women hospitalized with CM, and birth outcomes for infants of mothers hospitalized with CM to other California infants. We used multivariable logistic regression, controlling for demographics and comorbidities, to determine the risk of pregnancy on CM dissemination.ResultsWe identified 2,372 women with ≥1 CM hospitalization; 187 (8%) were pregnant/post-partum and there were 188 infants (one set of twins). Pregnant/post-partum women were more likely to be Hispanic (59% vs. 44%, P < 0.01), younger (median age 27 vs. 35 years, P < 0.01), without comorbidities (60% vs. 36%, P < 0.01), and have disseminated CM (32% vs. 21%, P < 0.01) than nonpregnant women. Hospitalized pregnant/post-partum women with CM were more likely to have CM dissemination compared with hospitalized non-pregnant women with CM (odds ratio 2.0, 95% confidence interval 1.4–2.8). Among infants of pregnant women hospitalized with CM, 18 (10%) were born < 34 weeks gestational age and 11 (8%) of 134 term (>37 weeks) infants had a birth weight <2,500 g; compared with 3% and 3% (P < 0.01) of other California liveborns, respectively.ConclusionThis study is the largest cohort of pregnant women hospitalized with CM to date and corroborates that pregnant/post-partum women are more likely to develop disseminated CM than non-pregnant women. Their infants may be more likely to be born <34 weeks gestational age and have a low birth weight. This highlights the need for clinicians caring for pregnant/post-partum women who may live or travel to an area where CM occurs to be aware of the risks for these women and their infants.Disclosures All authors: No reported disclosures.

Trauma in pregnancy and severe adverse perinatal outcomes

Background Trauma, including accidental and violent trauma, is a rare but severe complication of pregnancy. The incidence of adverse perinatal outcomes in pregnancies affected by traumatic injury has not been well-studied. Objective We sought to characterize the association between traumatic injury during pregnancy and severe adverse perinatal outcomes in a large population. Study design We performed a retrospective cohort study of California Birth Registry data from 2007 to 2011. ICD-9 diagnosis and procedure codes were used to categorize patients into trauma and non-trauma cohorts and to assess the prevalence of severe adverse fetal and neonatal outcomes. Chi-square tests were used to characterize maternal demographics and perform univariate analyses, and logistic regression was used to control for potential confounders. Results Of 2,406,605 singleton nonanomalous pregnancies, 1262 (0.05%) experienced trauma prior to delivery. The rate of composite perinatal outcomes was higher in pregnancies with trauma compared to those without (3.1 versus 0.87%, p < .001). Trauma was associated with higher occurrences of preterm birth <37 weeks, preterm birth <32 weeks, very low birth weight and neonatal death. Fetal demise at any gestational age was more common among trauma patients (1.9 versus 0.53%, p < .001), though this difference was not statistically significant among term fetuses (0.28 versus 0.14%, p = .21). A difference in composite adverse perinatal outcomes was seen even after controlling for important maternal characteristics (aOR 3.2, 95% CI). Trauma patients with severe morbidity compared to those without had higher rates of preterm birth <37 weeks, preterm birth <32 weeks, and composite severe perinatal outcomes. Conclusion Trauma in pregnant women is associated with an increased risk of severe adverse perinatal outcomes, including fetal and neonatal demise. Prevalence of fetal demise is not different between trauma and non-trauma mothers when looking at term fetuses only, suggesting that the greatest risk of fetal demise in the setting of trauma occurs in the preterm period. These data can be used to counsel patients and to inform more detailed research into the mechanisms of trauma in pregnancy outcomes.

Racial/ethnic disparities in critical periods of vulnerability to fine particulate matter during pregnancy

TPS 743: Health effects in pregnancy, Exhibition Hall, Ground floor, August 26, 2019, 3:00 PM - 4:30 PM Background: Exposure to ambient fine particulate matter (PM2.5) during pregnancy is associated with preterm birth (PTB), a leading cause of infant morbidity and mortality. Recent studies have attempted to identify periods of susceptibility to PM2.5 during pregnancy. This study aims to identify racial/ethnic disparities in critical periods of susceptibility to PM2.5 during pregnancy. Methods: We linked all live singleton births in California from 2005 – 2010 with weekly average PM2.5 (μg/m3) exposure during pregnancy. Associations between PM2.5 and preterm birth were assessed using multi-level distributed lag Cox proportional hazard models and a distributed lag model. We also assessed effect measure modification by non-Hispanic White, non-Hispanic Black and Hispanic race/ethnicity by calculating the weekly relative excess risk due to interaction (RERI). Results: Gestational weeks 17-24 and 36 were associated with increased vulnerability to PM2.5 exposure across all pregnancies. We find that non-Hispanic Black mothers may be more susceptible to PM2.5 exposure effects when compared with non-Hispanic White mothers, particularly during weeks 28-33 of pregnancy. Conclusions: These findings extend our knowledge about the existence of specific susceptibility exposure periods during pregnancy that may differ across race/ethnic groups which can help to inform targeted prevention efforts among racial/ethnic subgroups.

Exposure to traffic related air pollution in pregnancy and infancy in relation to autism spectrum disorder in California

PDS 73: Neurological effects, Johan Friso Foyer, Floor 1, August 26, 2019, 10:30 AM - 12:00 PM Background/Aim: Studies are accumulating that suggest associations between air pollutants and autism spectrum disorder (ASD) in children. However, most studies include rather small numbers of cases. Our objective was to conduct a statewide study in California focusing on road traffic related exposure during pregnancy and the first year of life to assess related risks for childhood ASD. Methods: We used a population based registry linkage design including state-wide California birth data retrieved from Office of Vital Statistics birth data 1998-2010. ASD (during the study period assessed as autistic disorder (DSM IV-R)) cases (n= 30,514) were identified through records maintained at the California Department of Developmental Services and linked to birth records. Birth record controls were matched on sex and year 1:10. Exposure to road traffic related CO, NOx and PM2.5 concentrations during pregnancy and first year of life were estimated using the California Line Source Dispersion Model 4, a modified Gaussian line-source dispersion model. We estimated unadjusted and adjusted odds ratios (OR) and 95% confidence intervals (CI) using logistic regression. Results: Exposure to interquartile-range increases of the correlated pollutants CO, NOx and PM2.5 related to increased ORs for ASD of 10-13% (e.g. NOx: OR=1.11; 95% CI:1.10,1.12) for prenatal and similarly for infant exposure, adjusting for maternal age, education, race/ethnicity, maternal birth place and other potential confounders. Including prenatal and infant exposure in the same model suggested potentially stronger associations for infant exposure. Conclusions: Our state-wide population based study including a large number of ASD cases and avoiding self-selection bias, indicates small to moderately increased risks for ASD related to pregnancy and early life exposure to traffic generated air pollution. These findings confirm and extend earlier smaller studies suggesting the need for public health policies to regulate air pollution exposure to protect populations from the adverse impacts on the developing fetus.

Trends in maternal prepregnancy body mass index (BMI) and its association with birth and maternal outcomes in California, 2007–2016: A retrospective cohort study

ObjectiveTo determine recent trends in maternal prepregnancy body mass index (BMI) and to quantify its association with birth and maternal outcomes.MethodsA population-based retrospective cohort study included resident women with singleton births in the California Birth Statistical Master Files (BSMF) database from 2007 to 2016. There were 4,621,082 women included out of 5,054,968 women registered in the database. 433,886 (8.6%) women were excluded due to invalid or missing information for BMI. Exposures were underweight (BMI < 18.5 kg/m2), normal weight (18.5–24.9 kg/m2), overweight (25.0–29.9 kg/m2), and obese (≥ 30 kg/m2) at the onset of pregnancy. Obesity was subcategorized into class I (30.0–34.9 kg/m2), class II (35.0–39.9 kg/m2), and class III (≥ 40 kg/m2), while adverse outcomes examined were low birth weight (LBW), very low birth weight (VLBW), macrosomic births, preterm birth (PTB), very preterm birth (VPTB), small-for-gestational-age birth (SGA), large-for-gestational-age birth (LGA), and cesarean delivery (CD). Descriptive analysis, simple linear regression, and multivariate logistic regression were performed, and adjusted odds ratios (AORs) with 95% confidence intervals (CIs) for associations were estimated.ResultsOver the ten-year study period, the prevalence of underweight and normal weight women at time of birth declined by 10.6% and 9.7%, respectively, while the prevalence of overweight and obese increased by 4.3% and 22.9%, respectively. VLBW increased significantly with increasing BMI, by 24% in overweight women and by 76% in women with class III obesity from 2007 to 2016. Women with class III obesity also had a significant increase in macrosomic birth (170%) and were more likely to deliver PTB (33%), VPTB (66%), LGA (231%), and CD (208%) than women with a normal BMI. However, obese women were less likely to have SGA infants; underweight women were 51% more likely to have SGA infants than women with a normal BMI.ConclusionsIn California from 2007 to 2016, there was a declining trend in women with prepregnancy normal weight, and a rising trend in overweight and obese women, particularly obesity class III. Both extremes of prepregnancy BMI were associated with an increased incidence of adverse neonatal outcomes; however, the worse outcomes were prominent in those women classified as obese.

Rate and causes of severe maternal morbidity at readmission: California births in 2008-2012.

To determine the rate, maternal characteristics, timing, and indicators of severe maternal morbidity (SMM) that occurs at postpartum readmission. Women with a birth in California during 2008-2012 were included in the analysis. Readmissions up to 42 days after delivery were investigated. SMM was defined as presence of any of the 21 indicators defined by ICD-9 codes. Among 2,413,943 women with a birth, SMM at readmission occurred in 4229 women. Of all SMM, 12.1% occurred at readmission. Over half (53.5%) of the readmissions with SMM occurred within the first week after delivery hospitalization. The most common indicators of SMM were blood transfusion, sepsis, and pulmonary edema/acute heart failure. Twelve percent of SMM was identified at readmission with the majority occurring within 1 week after discharge from delivery hospitalization. Because early readmission may reflect lack of discharge readiness, there may be opportunities to improve care.

A quantile regression approach to examine fine particles, term low birth weight, and racial/ethnic disparities.

Exposure to fine particulate matter (PM2.5) during pregnancy has been shown to be associated with reduced birth weight and racial/ethnic minorities have been found to be more vulnerable. Previous studies have focused on the mean value of birth weight associated with PM2.5, which may mask meaningful differences. We applied a quantile regression approach to investigate the variation by percentile of birth weight and compared non-Hispanic (NH) Black, NH White, and Hispanic mothers. Data for singleton births in California from October 24, 2005 to February 27, 2010 were collected from the birth records accessed from the California Department of Public Health. Air pollution monitoring data collected by the California Air Resources Board and interpolated for each zip code using an inverse-distance weighting approach, and linked to maternal zip code of residence reported on the birth certificate. Multilevel linear regression models were conducted with mother's residential zip code tabulation area as a random effect. Multilevel quantile regression models were used to analyze the association at different percentiles of birth weight (5th, 10th, 25th, 50th, 75th, 90th, 95th), as well as examine the heterogeneity in this association between racial/ethnic groups. Linear regression revealed that a 10 μg/m3 increase in PM2.5 exposure during pregnancy is associated with a mean birth weight decrease of 7.31 g [95% confidence interval (CI): 8.10, 6.51] and NH Black mothers are the most vulnerable. Results of the quantile regression are not constant across quantiles. For NH Black mothers whose infants had the lowest birthweight of less than 2673 g (5th percentile), a 10 μg/m3 increase in PM2.5 exposure is associated with a decrease of 18.57 g [95% CI: 22.23, 14.91], while it is associated with a decrease of 7.77 g [95% CI: 8.73, 6.79] for NH White mothers and 7.76 [8.52, 7.00] decrease for Hispanic mothers at the same quantile. Results of the quantile regression revealed greater disparities, particularly for infants with the lowest birth weight. By identifying vulnerable populations, we can promote and implement policies to confront these health disparities.

Smoking during Pregnancy and Adverse Birth and Maternal Outcomes in California, 2007 to 2016.

This study aimed to determine associations between maternal cigarette smoking and adverse birth and maternal outcomes. This is a 10-year population-based retrospective cohort study including 4,971,896 resident births in California. Pregnancy outcomes of maternal smokers were compared with those of nonsmokers. The outcomes of women who stopped smoking before or during various stages of pregnancy were also investigated. Infants of women who smoked during pregnancy were twice as likely to have low birth weight (LBW) and be small for gestational age (SGA), 57% more likely to have very LBW (VLBW) or be a preterm birth (PTB), and 59% more likely to have a very PTB compared with infants of nonsmokers. During the study period, a significant widening of gaps developed in both rates of LBW and PTB and the percentage of SGA between infants of maternal smokers and nonsmokers. Smoking during pregnancy is associated with a significantly increased risk of adverse birth and maternal outcomes, and differences in rates of LBW, PTB, and SGA between infants of maternal smokers and nonsmokers increased during this period. Stopping smoking before pregnancy or even during the first trimester significantly decreased the infant risks of LBW, PTB, SGA, and the maternal risk for cesarean delivery.