California Birth Research Articles

A population-based study to identify the prevalence and correlates of the dual burden of severe maternal morbidity and preterm birth in California

Background Prior studies have documented associations between preterm birth and severe maternal morbidity (SMM) but the prevalence and correlates of dual burden are not adequately understood, despite significant family implications. Purpose To describe the prevalence and correlates of the dual burden of SMM and preterm birth and to understand profiles of SMM by dual burden of preterm birth. Approach: This retrospective cohort study included all California live births in 2007–2012 with gestations 20–44 weeks and linked to a birth cohort database maintained by the California Office of Statewide Health Planning and Development (n = 3,059,156). Dual burden was defined as preterm birth (<37 weeks) with severe maternal morbidity (SMM, defined by Centers for Disease Control). Predictors for dual burden were assessed using Poisson logistic regression, accounting for hospital variance. Results Rates of preterm birth and SMM were 876 and 140 per 10,000 births, respectively. The most common indications of SMM both with and without preterm birth were blood transfusions and a combination of cardiac indications. One-quarter of women with SMM experienced preterm birth with a dual burden rate of 37 per 10,000 births. Risk of dual burden was over threefold higher with cesarean birth (primiparous primary aRR = 3.3, CI = 3.0–3.6; multiparous primary aRR = 8.1, CI = 7.2–9.1; repeat aRR = 3.9, CI = 3.5–4.3). Multiple gestation conferred a six-fold increased risk (aRR = 6.3, CI = 5.8–6.9). Women with preeclampsia superimposed on gestational hypertension (aRR = 7.3, CI = 6.8–7.9) or preexisting hypertension (aRR = 11.1, CI = 9.9–12.5) had significantly higher dual burden risk. Significant independent predictors for dual burden included smoking during pregnancy (aRR = 1.5, CI = 1.4–1.7), preexisting hypertension without preeclampsia (aRR = 3.3, CI = 3.0–3.7), preexisting diabetes (aRR = 2.6, CI = 2.3–3.0), Black race/ethnicity (aRR = 2.0, CI = 1.8–2.2), and prepregnancy body mass index <18.5 (aRR = 1.4, CI = 1.3–1.5). Conclusions Dual burden affects 1900 California families annually. The strongest predictors of dual burden were hypertensive disorders with preeclampsia and multiparous primary cesarean.

Strong upward neighborhood mobility and preterm birth: a matched-sibling design approach

PurposeMuch cross-sectional work reports an association between neighborhood disadvantage and adverse birth outcomes. Limitations of this work include that mothers with pre-existing unmeasured morbidity may “select” into, or out of, certain neighborhoods. This selection issue remains a key rival explanation for work concerned with place-based disparities in birth outcomes. We move beyond a cross-sectional approach and exploit a sibling-linked data set in California to test whether upwardly mobile mothers, who move from a very high to a very low disadvantaged neighborhood, exhibit a lower than expected risk of preterm birth (PTB) (i.e., delivery <37 weeks). MethodsWe used a matched-sibling design for 461,061 sibling pairs (i.e., 922,122 births total) to mothers in urban areas in who gave birth in California from 2005 to 2010. We linked mother's address at two time points (i.e., two sibling birth dates) to a census-derived composite indicator of neighborhood disadvantage. Conditional logistic regression methods controlled for mother's risk of PTB in the sibling delivered before the move when estimating the relation between strong upward mobility and preterm of the subsequent birth after the move. ResultsAs hypothesized, strong upward mobility (relative to no mobility) varies inversely with the odds of PTB of the second sibling (odds ratio [OR] for PTB = 0.83, 95% confidence interval: 0.74, 0.93). ConclusionsMothers moving from very high to very low disadvantaged neighborhoods show a reduced odds of PTB. Our findings, if replicated, raise the possibility that improvements in neighborhood quality may improve perinatal health in a relatively short time span.

An Evaluation of Sexually Transmitted Infection and Odds of Preterm or Early-Term Birth Using Propensity Score Matching.

Few studies have examined the relationship between sexually transmitted infections (STIs) and preterm birth (<37 weeks gestation) by subtype (<32 weeks, 32-36 weeks, spontaneous, provider-initiated). Here, we evaluate the odds of preterm (by subtype) and early-term (37 and 38 weeks gestation) birth in women with an STI compared with a propensity score-matched reference population. The sample was selected from California births in 2007 to 2012. Sexually transmitted infection was defined as a maternal diagnosis of chlamydia, gonorrhea, or syphilis in the birth certificate or hospital discharge record. A reference sample of women without an STI was selected using exact propensity score matching on maternal factors. Odds of preterm and early-term birth were calculated. Sixteen thousand three hundred twelve women were identified as having an STI during pregnancy and an exact propensity score-matched control was identified for 97.2% (n = 15,860). Women with an indication of syphilis during pregnancy were at 1.6 times higher odds of having a preterm birth and, in particular, at elevated odds of a birth less than 32 weeks due to preterm premature rupture of the membranes or provider-initiated birth (odds ratios 4.0-4.2). Women with gonorrhea were at increased odds of a preterm birth, a birth less than 32 weeks, or an early-term birth (odds ratios 1.2-1.8). Chlamydia did not raise the odds of either a preterm or early-term birth. Gonorrhea and syphilis increased the odds of a preterm birth. Gonorrhea also increased the odds of an early-term birth. Chlamydia did not raise the odds of an early birth.

Ambient Fine Particulate Matter and Preterm Birth in California: Identification of Critical Exposure Windows.

Exposure to ambient fine particulate matter (particulate matter ≤2.5 μm in aerodynamic diameter (PM2.5)) during pregnancy is associated with preterm birth (PTB), a leading cause of infant morbidity and mortality. Results from studies attempting to identify etiologically relevant exposure periods of vulnerability have been inconsistent, possibly because of failure to consider the time-to-event nature of the outcome and lagged exposure effects of PM2.5. In this study, we aimed to identify critical exposure windows for weekly PM2.5 exposure and PTB in California using California birth cohort data from 2005-2010. Associations were assessed using distributed-lag Cox proportional hazards models. We assessed effect-measure modification by race/ethnicity by calculating the weekly relative excess risk due to interaction. For a 10-μg/m3 increase in PM2.5 exposure over the entire period of gestation, PTB risk increased by 11% (hazard ratio = 1.11, 95% confidence interval: 1.09, 1.14). Gestational weeks 17-24 and 36 were associated with increased vulnerability to PM2.5 exposure. We find that non-Hispanic black mothers may be more susceptible to effects of PM2.5 exposure than non-Hispanic white mothers, particularly at the end of pregnancy. These findings extend our knowledge about the existence of specific exposure periods during pregnancy that have the greatest impact on preterm birth.

The Impact of Limited Prenatal Care on Pregnancy Outcomes in Women With Depression [32A

INTRODUCTION: Depression is associated with a number of risks in pregnancy. This study aimed to examine how the number of prenatal care visits impacts pregnancy outcomes in women with depression. METHODS: This is a retrospective cohort study of singleton, non-anomalous births in California between 2007 and 2011 to compare outcomes of all women with depression who had 5 or more prenatal care visits compared with those with less than 5 visits. Outcomes included preterm delivery, intrauterine fetal demise, neonatal death, neonatal respiratory distress syndrome, placental abruption, maternal blood transfusion, and CDC severe maternal morbidity index score. To compare outcomes, we used chi-square and multivariate logistic regression controlling for socioeconomic status, age, parity, gestational age, ethnicity, diabetes, and hypertension. RESULTS: Of the 18,511 women with depression in our sample, those with limited prenatal care had higher risk of placental abruption, intrauterine fetal demise, preterm delivery, low birthweight (<2500 grams), neonatal respiratory distress syndrome, and severe maternal morbidity. Rates of neonatal death were significantly higher in the chi-square analysis (0.81% vs 0.15%, p = 0.002), however this difference did not persist in the multivariate analysis when controlling for potential confounding variables. CONCLUSION: In women with depression during pregnancy, limited prenatal care is associated with greater odds of adverse neonatal and maternal outcomes, including intrauterine fetal demise and severe maternal morbidity. These associations should be considered when providing care to pregnant women with depression. Additionally, further examination of the obstacles limiting access to regular prenatal care in this patient population should be pursued.

Development and validation of a clinical model for preconception and early pregnancy risk prediction of gestational diabetes mellitus in nulliparous women.

Implementation of dietary and lifestyle interventions prior to and early in pregnancy in high risk women has been shown to reduce the risk of gestational diabetes mellitus (GDM) development later in pregnancy. Although numerous risk factors for GDM have been identified, the ability to accurately identify women before or early in pregnancy who could benefit most from these interventions remains limited. As nulliparous women are an under-screened population with risk profiles that differ from their multiparous counterparts, development of a prediction model tailored to nulliparous women may facilitate timely preventive intervention and improve maternal and infant outcomes. We aimed to develop and validate a model for preconception and early pregnancy prediction of gestational diabetes mellitus based on clinical risk factors for nulliparous women. A risk prediction model was built within a large California birth cohort including singleton live birth records from 2007–2012. Model accuracy was assessed both internally and externally, within a cohort of women who delivered at University of Iowa Hospitals and Clinics between 2009–2017, using discrimination and calibration. Differences in predictive accuracy of the model were assessed within specific racial/ethnic groups. The prediction model included five risk factors: race/ethnicity, age at delivery, pre-pregnancy body mass index, family history of diabetes, and pre-existing hypertension. The area under the curve (AUC) for the California internal validation cohort was 0.732 (95% confidence interval (CI) 0.728, 0.735), and 0.710 (95% CI 0.672, 0.749) for the Iowa external validation cohort. The model performed particularly well in Hispanic (AUC 0.739) and Black women (AUC 0.719). Our findings suggest that estimation of a woman’s risk for GDM through model-based incorporation of risk factors accurately identifies those at high risk (i.e., predicted risk >6%) who could benefit from preventive intervention encouraging prompt incorporation of this tool into preconception and prenatal care.

Impact of autoimmune rheumatic diseases on birth outcomes: a population-based study

ObjectivesAutoimmune rheumatic diseases (ARDs) affect women of childbearing age and have been associated with adverse birth outcomes. The impact of diseases like ankylosing spondylitis and psoriatic arthritis (PsA) on birth...

Residential mobility in early childhood and the impact on misclassification in pesticide exposures

Studies of environmental exposures and childhood cancers that rely on records often only use maternal address at birth or address at cancer diagnosis to assess exposures in early childhood, possibly leading to exposure misclassification and questionable validity due to residential mobility during early childhood.Our objective was to assess patterns and identify factors that may predict residential mobility in early childhood, and examine the impact of mobility on early childhood exposure assessment for agriculturally applied pesticides and childhood cancers in California.We obtained the addresses at diagnosis of all childhood cancer cases born in 1998–2011 and diagnosed at 0–5 years of age (n = 6478) from the California Cancer Registry (CCR), and their birth addresses from linked birth certificates. Controls were randomly selected from California birth records and frequency matched (20:1) to all cases by year of birth. We obtained residential histories from a public-record database LexisNexis for both case (n = 3877 with age at diagnosis 1–5 years) and control (n = 99,262) families. Logistic regression analyses were conducted to assess the socio-demographic factors in relation to residential mobility in early childhood. We employed a Geographic Information System (GIS)-based system to estimate children's first year of life exposures to agriculturally applied pesticides based on birth vs diagnosis address or residential histories based upon Lexis-Nexis Public Records and assessed agreement between exposure measures using Spearman correlations and kappa statistics.Over 20% of case and control children moved in their first year of life, and 55% of children with cancer moved between birth and diagnosis. Older age at diagnosis, younger maternal age, lower maternal education, not having a Hispanic ethnic background, use of public health insurance, and non-metropolitan residence at birth were predictors of higher residential mobility. There was moderate to strong correlation (Spearman correlation = 0.76–0.83) and good agreement (kappa = 0.75–0.81) between the first year of life exposure estimates for agricultural pesticides applied within 2 km of a residence relying on an address at birth or at diagnosis or LexisNexis addresses; this did not differ by outcome status, but agreement decreased with decreasing buffer size, and increasing distance moved or age at diagnosis.These findings suggest that residential addresses collected at one point in time may represent residential history in early childhood to a reasonable extent; nevertheless, they exposure misclassification in the first year of life remains an issue. Also, the highest proportion of women not captured by LexisNexis were Hispanic women born in Mexico and those living in the lowest SES neighborhoods, i.e. possibly those with the higher environmental exposures, as well as younger women and those with less than high school education.Though LexisNexis only captures a sub-population, its data may be useful for augmenting address information and assessing the extent of exposure misclassification when estimating environmental exposures in large record linkage studies. Future research should investigate how to correct for exposure misclassification introduced by residential mobility that is not being captured by records.

Medical indications for primary cesarean delivery in women with and without disabilities

Background: Prior research has found that women with disabilities are more likely to deliver by cesarean than are women without disabilities. It is not clear whether all of the cesarean deliveries among women with disabilities are medically necessary.Objectives: To examine the associations between maternal disability status and type, mode of delivery, and medical indications for cesarean delivery in California deliveries.Study design: Retrospective cohort study of all nulliparous births in California between 2000 and 2012. We classified births as to whether or not women underwent a trial of labor and determined if medical indications for cesarean delivery were present. Multivariable logistic regression models examined the association of disability with trial of labor and indications for cesarean delivery.Results: Women with disabilities had lower odds of having a labored delivery, compared to women without disabilities (adjusted odds ratio (aOR) = 0.45, 95% confidence interval (CI) 0.41–0.49). In the sample of women who labored (90.5% of total), women with disabilities were more likely to have a medical indication for cesarean delivery (aOR = 1.15, 95% CI 1.10–1.21) and were more likely to have a cesarean delivery (aOR = 1.46, 95% CI = 1.38–1.54). In the subsample of unlabored cesarean deliveries, women with disabilities were less likely to have documented medical indications for cesarean delivery (aOR = 0.45, 95% CI = 0.41–0.50).Conclusions: Women with disabilities were less likely to labor, and these unlabored cesarean deliveries were less likely to have a medical indication for cesarean, compared to women without disabilities.

Differences in Prenatal Care by Presence and Type of Maternal Disability

Prior studies have found that women with disabilities are less likely to receive adequate prenatal care than women without disabilities. However, little is known about differences in patterns of prenatal care by type of disability. Therefore, this study examined timing and frequency of prenatal care among women with physical, sensory, or intellectual/developmental disabilities compared with women without disabilities. This was a retrospective cohort study using linked maternal and infant hospital discharge and birth certificate data for all births in California in 2000-2012 (N=6,745,201). Analyses were conducted in 2017-2018. Modified Poisson regression analyses compared women with each type of disability with women without disabilities on trimester of prenatal care initiation and number of prenatal care visits. Women with intellectual/developmental disabilities or with limited hearing had significantly higher RR of delaying prenatal care initiation until the second or third trimester (intellectual/developmental disabilities: adjusted RR=1.21, 95% CI=1.09, 1.33; hearing: adjusted RR=1.11, 95% CI=1.02, 1.21), whereas women with physical disabilities and limited vision had lower risk of delaying care (physical: adjusted RR=0.91, 95% CI=0.88, 0.94; vision: adjusted RR=0.85, 95% CI=0.73, 0.99). Women with limited hearing or vision or intellectual/developmental disabilities had higher risk of receiving fewer prenatal visits than recommended, compared with women without disabilities. Women with physical disabilities or intellectual/developmental disabilities had higher RR of receiving more than the typical number of visits. There were key differences in prenatal care utilization by disability type, reflective of particularly pronounced disparities for women with intellectual/developmental disabilities and women with limited hearing. Delays in receipt of prenatal care and low numbers of prenatal care visits may contribute to the poorer birth outcomes that have been observed previously in these groups. Targeted interventions are needed to improve uptake of prenatal care in these vulnerable populations.

La douleur, quelle chose étrange. Scénariste : Steve Haines, illustratrice : Sophie Standing. Paris: Éditions çà et là; 2018

Previous studies have demonstrated associations between fine particulate matter (PM2.5) and risk of term low birth weight (TLBW; birth weight < 2500 g and gestational weeks ≥ 37 weeks). However, it remains unclear which PM2.5 sources mainly contribute to these associations, and which subgroups (e.g. by residential region and maternal characteristics) may be more susceptible to these exposures. Using California birth records and PM2.5 data from eight monitoring sites from 2002 to 2009, we examined the relationship between exposures to total PM2.5 and PM2.5 sources and risk of TLBW. Source apportionment was performed for each site using Positive Matrix Factorization, and five PM2.5 sources (i.e., secondary ammonium sulfate, secondary ammonium nitrate, vehicular emissions, biomass burning, and resuspended soil) were included in our analysis. Mean gestational and trimester exposures were calculated for mothers with ZIP codes located within a 20 km radius of monitors (N = 1,050,330). Logistic regression was conducted and adjusted for maternal age, race/ethnicity, and education, as well as gestational age, year of birth, apparent temperature exposure during gestation, and neighborhood level percentage of households below poverty level. Increased risks of TLBW associated with each interquartile range increase in exposure were 4.9% (95% confidence interval: 2.6, 7.3) for total PM2.5, 7.7% (4.7, 10.7) for secondary ammonium sulfate, 5.6% (3.5, 7.7) for resuspended soil, and 3.1% (1.3, 4.9) for secondary ammonium nitrate. Differences in associations were found between inland and coastal regions, and between northern and southern regions for several sources. Results also showed effect measure modification by maternal race/ethnicity and education, with the lowest risk of TLBW associated with PM2.5 exposures found in mothers with at least a college education and Asian mothers. Some PM2.5 sources may be more harmful than others, and a better understanding of the relative toxicity of PM2.5 from each source could lead to more targeted and cost-effective regulations to protect public health.

Women's periconceptional lowered carbohydrate intake and NTD-affected pregnancy risk in the era of prefortification with folic acid.

A recent study observed women's restricted carbohydrate diet in the year before conception was associated with increased risk of neural tube defect (NTD)-affected pregnancies. That study corresponded to the era of postfortification of folic acid. Because folic acid and carbohydrate measures would derive from similar foods, investigators of that study could not determine whether the increased risk with restricted carbohydrate intake was a consequence of lower folate intake. We extend their novel observation by examining rigorous NTD data prior to folic acid fortification. Data were derived from a population-based case-control study of fetuses and infants with NTDs among 1989-1991 California births. Interviews were conducted with mothers of 449 NTD cases and with mothers of 458 nonmalformed controls. A standard 100-item food frequency questionnaire was used to assess macro- and micronutrient intakes based on reported intakes 3 months before conception. Case mothers were twice as likely to have consumed a low carbohydrate (≤5th percentile intake among controls) diet with a crude odds ratio of 2.0 (95% confidence interval, 1.2-3.4). Adjustment for race/ethnicity, education, alcohol intake, and folic acid use made very little difference on the odds ratio. Adjustment for total energy intake appeared to be the only factor to slightly attenuate the odds ratio. Our findings indicate that the association between low carbohydrate intake and NTD risk may not be wholly a function of low folic acid in the postfortification era. Such a finding offers new clues to pursue for the seemingly folate-insensitive NTDs that continue to occur.

The contribution of maternal characteristics and cesarean delivery to an increasing trend of severe maternal morbidity

BackgroundSevere maternal morbidity – life-threatening childbirth complications – has more than doubled in the United States over the past 15 years, affecting more than 50,000 women (1.4% of deliveries) annually. During this time period, maternal age, obesity, comorbidities, and cesarean delivery also increased and may be related to the rise in severe maternal morbidity. We sought to evaluate: (1) the association of advanced maternal age, pre-pregnancy obesity, pre-pregnancy comorbidities, and cesarean delivery with severe maternal morbidity, and (2) whether changes in the prevalence of these risk factors affected the trend of severe maternal morbidity.MethodsThis population-based cohort study used linked birth record and patient discharge data from live births in California during 2007–2014 (n = 3,556,206). We used multivariable logistic regression models to assess the association of advanced maternal age (≥35 years), pre-pregnancy obesity (body mass index ≥30 kg/m2), pre-pregnancy comorbidity (index of 12 conditions), and cesarean delivery with severe maternal morbidity prevalence and trends. Severe maternal morbidity was identified by an index of 18 diagnosis and procedure indicators. We estimated odds ratios, predicted prevalence, and population attributable risk percentages.ResultsThe prevalence of severe maternal morbidity increased by 65% during 2007–2014. Advanced maternal age, pre-pregnancy obesity, and pre-pregnancy comorbidity also increased during this period, but cesarean delivery did not. None of these risk factors affected the increasing trend of severe maternal morbidity. However, the pre-pregnancy risk factors together were estimated to contribute to 13% (95% confidence interval: 12, 14%) of severe maternal morbidity cases in the study population overall, and cesarean delivery was estimated to contribute to 37% (95% confidence interval: 36, 38%) of cases.ConclusionsPre-pregnancy health and cesarean delivery are important risk factors for severe maternal morbidity but do not explain an increasing trend of severe maternal morbidity in California during 2007–2014. Investigation of other potential contributors is needed in order to identify ways to reverse the trend of severe maternal morbidity.

Obstetric Outcomes in U.S. Veterans: Emerging Knowledge, Considerations, and Gaps.

In the post-9/11 era, the number of young women serving, and deploying, in the military grew rapidly; as they exit service, there is tremendous increase in reproductive-aged women Veterans. Here, we review the limited but growing research regarding Veterans' pregnancy and obstetric outcomes. U.S. women Veterans returning from deployment carry a high burden of physical and mental health conditions, and often trauma. As poor mental health is known to predict poorer maternal and infant sequelae, there are unique concerns around perinatal outcomes in Veterans. Accordingly, there is new attention to their reproductive risks and needs-evidenced by recent research and programmatic efforts within the VA. Emerging research suggests that the unique health profiles of pregnant Veterans, including prevalent posttraumatic stress disorder, predict increased risk of preterm birth, preeclampsia, and gestational diabetes. In the most contemporary large study, relying on California birth data, Veterans who relied on VA for their health care coverage were high risk, with increased rates of preeclampsia and Cesarean delivery. Additionally, Veterans' infants (compared with non-Veterans') were more likely to require NICU care. Additional research is needed to explore upstream factors leading to these poorer outcomes. Current effort to coordinate VA and non-VA care for Veteran mothers is warranted.

499: Depression is associated with increased rates of adverse perinatal outcomes in women with gestational diabetes

There is a known relationship of depression and pre-existing diabetes. We sought to determine the rates adverse perinatal outcomes in patients with gestational diabetes (GDM) and depressive disorder in comparison to non-depressed women. A retrospective cohort study comparing the rate of maternal and neonatal outcomes among singleton, non-anomalous births in California to women with or without the diagnosis of depression between 2007 and 2011. Among women with GDM, perinatal outcomes were analyzed using Chi square and multivariate logistic regression to compare frequencies of characteristics and outcomes and to determine the strength of association of depression and adverse perinatal outcomes. Statistical comparisons and a p-value of less than 0.05 was used to indicate statistical significance. Of the 170,572 women with GDM who delivered in California, 2,090 (1.22%) were diagnosed with depression. Depressed women with GDM had significantly increased rates of perinatal adverse outcomes including hypertensive disorders of pregnancy (preeclampsia or gHTN) (Adjusted Odds Ratio [aOR] 1.25, 95% CI 1.09- 1.43), cesarean delivery (aOR 0.99, 95% CI 0.88-1.11), stillbirths (aOR 1.28, 95% CI 0.68-2.42), and preterm delivery at <37, <34, and <32 weeks gestational age (aOR 1.33, 95% CI 1.18-1.50; 1.36, 95% CI 1.15-1.61; 1.22, 95% CI 0.99-1.51 respectively) (Table 1 and Figure 1). Women with GDM and a diagnosis of depression have higher frequencies of perinatal adverse outcomes. Whether early testing and diagnosis of GDM in this population can improve perinatal outcomes is unknown but should be considered a high-risk population for GDM.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

690: Racial disparities in preterm birth risk by risk factor grouping

To examine racial/ethnic differences in risk of preterm birth (PTB, < 37 weeks) among women with known risk factors. We used the California Birth Cohort Database for live births maintained by the California Office of State Health Planning and Development. Our sample included singleton deliveries between 20-44 weeks gestation among non- Hispanic “Black”, “Hispanic” White, and non-Hispanic “White” women. Risk groups were classified using ICD-9 codes for previous PTB, any hypertension, preeclampsia, any diabetes, infection, mental illness, smoking, and drug or alcohol dependence. We used logistic regression to compare odds of PTB in Black and Hispanic compared to White women among women who had none of these risk factors and among women with each risk factor. All models were adjusted for other risk factors and for maternal age, interpregnancy interval, education, obesity, and poverty status. 2,320,020 women were included in this analysis (7% Black, 61% Hispanic, and 32% White). PTB rates were higher among Black (9.9%) and Hispanic (6.9%) women compared to White women (6.0%, adjusted odds ratio [aOR] = 1.5 and aOR = 1.3, respectively). While PTB rates across risk groups differed dramatically (wherein the highest rates were among Black and Hispanic women with preeclampsia (33.0% and 29.5%, respectively)) or previous PTB (30.5% and 29.6%, respectively)), the magnitude of the disparities remained consistent for Black and Hispanic women compared to White women across most risk factor groupings (aORs 1.4 to 1.6 for Black versus White women and 1.2 to 1.3 for Hispanic versus White women). Exceptions included women who had a previous PTB (aOR of 1.1 for Black versus White women), any hypertension (aOR 1.5 for Hispanic versus White women), or smoked (aOR 1.1 for Hispanic versus White women). While all risk factors were associated with an increased risk of PTB across race/ethnicity groupings, these racial/ethnic disparities remained fairly similar suggesting that others factors (e.g., stress, racism) are driving disparities.

Parental age and stillbirth: a population-based cohort of nearly 10 million California deliveries from 1991 to 2011

PurposeParental age at delivery in the United States has been rising. Advanced maternal and paternal ages have been associated with adverse pregnancy outcomes including stillbirth. However, these relationships come from studies that often do not present results for both mother and father concurrently. The purpose of this study was to estimate the risk of stillbirth for maternal and paternal age in the same cohort of deliveries. MethodsThis is a population-based cohort study of all live birth and stillbirth deliveries in California from 1991 to 2011. The individual associations between maternal and paternal ages and stillbirth were estimated with hazard ratios from Cox proportional hazard models. Age was modeled continuously with restricted cubic splines to account for nonlinear relationships. Mean parental age was used as the referent group. ResultsJ-shaped associations between maternal and paternal ages were observed in crude models where older mothers and fathers had the highest hazard ratios for stillbirth. In maternal models, after adjusting for maternal and paternal covariates, young maternal age no longer showed increased hazard ratio for stillbirth, whereas the association with older mothers remained. In adjusted paternal models, the relationship between young paternal age and stillbirth was unchanged while the hazard ratio for older fathers was slightly smaller. ConclusionsAfter adjusting for both parents’ age, education, race/ethnicity, along with parity, older mothers and fathers were independently associated with elevated hazard ratios for stillbirth.

Maternal dyslipidemia and risk for preterm birth.

Maternal lipid profiles during pregnancy are associated with risk for preterm birth. This study investigates the association between maternal dyslipidemia and subsequent preterm birth among pregnant women in the state of California. Births were identified from California birth certificate and hospital discharge records from 2007–2012 (N = 2,865,987). Preterm birth was defined as <37 weeks completed gestation and dyslipidemia was defined by diagnostic codes. Subtypes of preterm birth were classified as preterm premature rupture of membranes (PPROM), spontaneous labor, and medically indicated, according to birth certificate data and diagnostic codes. The association between dyslipidemia and preterm birth was tested with logistic regression. Models were adjusted for maternal age at delivery, race/ethnicity, hypertension, pre-pregnancy body mass index, insurance type, and education. Maternal dyslipidemia was significantly associated with increased odds of preterm birth (adjusted OR: 1.49, 95%CI: 1.39, 1.59). This finding was consistent across all subtypes of preterm birth, including PPROM (adjusted OR: 1.54, 95%CI: 1.34, 1.76), spontaneous (adjusted OR: 1.51, 95%CI: 1.39, 1.65), and medically indicated (adjusted OR: 1.454, 95%CI: 1.282, 1.649). This study suggests that maternal dyslipidemia is associated with increased risk for all types of preterm birth.

High risk of spontaneous preterm birth among infants with gastroschisis.

We examined the association between gastroschisis and preterm birth (PTB, <37 weeks) by subtype. The sample was drawn from singleton live births in California from 2007 to 2012 contained in a birth cohort file maintained by the California Office of Statewide Health Planning and Development (n = 2,891,965; 1,421 with gastroschisis). Relative risks (RRs) and 95% confidence intervals (CIs) were calculated for PTB by gestational age (<34, 34-36, and any <37 weeks) and by type (spontaneous labor with intact membranes, preterm premature rupture of the membranes [PPROM], provider initiated) and were adjusted for maternal characteristics. Over 44.5% of infants with gastroschisis were born preterm because of spontaneous etiologies; notably, 8.4% of infants with gastroschisis were born <34 weeks because of spontaneous etiologies (adjusted RRs 9.1-12.2). Overall, 53.7% of infants with gastroschisis were born preterm compared with only 6.9% of infants without gastroschisis (adjusted RR 15.2, 95% CI 13.6-19.5) and are at particularly high risk of spontaneous PTB. Nearly 9% of infants with gastroschisis delivered <34 weeks, regardless of preterm etiology, indicating that these infants are at great risk for PTB morbidities in addition to the complications from gastroschisis.

An Examination of Preterm Birth and Residential Social Context among Black Immigrant Women in California, 2007-2010.

The foreign-born black population contributes a considerable amount of heterogeneity to the US black population. In 2005, black immigrants accounted for 20% of the US black population. Compared to native-born black women, black immigrant women are at lower risk for adverse birth outcomes, including preterm birth. Some scholars posit that differential exposures to socioeconomic disadvantage and structural racism in the residential context may account for this advantage. However, to date, few studies offer comprehensive examinations of the black immigrant residential social context, particularly in settlement regions beyond predominantly black and historically segregated regions. Further, studies examining the black immigrant residential context typically use a single indicator, which limits discussion of the intersecting domains that simultaneously increase or decrease risk among black immigrants. We addressed these gaps by examining black immigrant neighborhoods in the state of California, where racial residential segregation of the black population is low. We operationalized the residential context of black immigrant women using three distinct attributes: immigrant co-ethnic density, black racial concentration, and neighborhood deprivation. We linked 2007-2010 California birth records of black immigrant women and 2010 census data on tract-level social attributes (N = 6930). OLS regression analyses showed that immigrant co-ethnic density, black racial concentration and neighborhood deprivation were not associated with preterm birth among black immigrants. Our findings indicate that in California, residential social context has little relation to black immigrant preterm birth-a finding that is unique compared to residential settings of other settlement contexts.