Racial and Ethnic Inequities in Therapeutic Hypothermia and Neonatal Hypoxic-Ischemic Encephalopathy: A Retrospective Cohort Study.

OBJECTIVE: To investigate racial inequities in the use of therapeutic hypothermia (TH) and outcomes in infants with hypoxic-ischemic encephalopathy (HIE). STUDY DESIGN: We queried an administrative birth cohort of mother-baby pairs in California from 2010 through 2019 using International Classification of Diseases codes to evaluate the association between race and ethnicity and the application of TH in infants with HIE. We identified 4779 infants with HIE. Log-linear regression was used to calculate risk ratios (RR) for TH, adjusting for hospital transfer, rural location, gestational age between 35 and 37 weeks, and HIE severity. Risk of adverse infant outcome was calculated by race and ethnicity and stratified by TH. RESULTS: From our identified cohort, 1338 (28.0%) neonates underwent TH. White infants were used as the reference sample, and 410 (28.4%) received TH. Black infants were significantly less likely to receive TH with 74 (20.0%) with an adjusted risk ratio (aRR) of 0.7 (95% CI 0.5-0.9). Black infants with any HIE who did not receive TH were more likely to have a hospital readmission (aRR 1.36, 95% CI 1.10-1.68) and a tracheostomy (aRR 3.07, 95% CI 1.19-7.97). Black infants with moderate/severe HIE who did not receive TH were more likely to have cerebral palsy (aRR 2.72, 95% CI 1.07-6.91). CONCLUSIONS: In this study cohort, Black infants with HIE were significantly less likely to receive TH. Black infants also had significantly increased risk of some adverse outcomes of HIE. Possible reasons for this inequity include systemic barriers to care and systemic bias.

Risk of Adverse Perinatal Outcomes Among African-born Black Women in California, 2011-2020.

BACKGROUND: African-born women have a lower risk of preterm birth and small for gestational age (SGA) birth compared with United States-born Black women, however variation by country of origin is overlooked. Additionally, the extent that nativity disparities in adverse perinatal outcomes to Black women are explained by individual-level factors remains unclear. METHODS: We conducted a population-based study of nonanomalous singleton live births to United States- and African-born Black women in California from 2011 to 2020 (n = 194,320). We used age-adjusted Poisson regression models to estimate the risk of preterm birth and SGA and reported risk ratios (RR) and 95% confidence intervals (CI). Decomposition using Monte Carlo integration of the g-formula computed the percentage of disparities in adverse outcomes between United States- and African-born women explained by individual-level factors. RESULTS: Eritrean women (RR = 0.4; 95% CI = 0.3, 0.5) had the largest differences in risk of preterm birth and Cameroonian women (RR = 0.5; 95% CI = 0.3, 0.6) in SGA birth, compared with United States-born Black women. Ghanaian women had smaller differences in risk of preterm birth (RR = 0.8; 95% CI = 0.7, 1.0) and SGA (RR = 0.9; 95% CI = 0.8, 1.1) compared with United States-born women. Overall, we estimate that absolute differences in socio-demographic and clinical factors contributed to 32% of nativity-based disparities in the risk of preterm birth and 26% of disparities in SGA. CONCLUSIONS: We observed heterogeneity in risk of adverse perinatal outcomes for African- compared with United States-born Black women, suggesting that nativity disparities in adverse perinatal outcomes were not fully explained by differences in individual-level factors.

Structural racism, nativity and risk of adverse perinatal outcomes among Black women.

BACKGROUND: Black women in the United States (US) have the highest risk of preterm birth (PTB) and small for gestational age (SGA) births, compared to women of other racial groups. Among Black women, there are disparities by nativity whereby foreign-born women have a lower risk of PTB and SGA compared to US-born women. Differential exposure to racism may confer nativity-based differences in adverse perinatal outcomes between US- and foreign-born Black women. This remains unexplored among US- and African-born women in California. OBJECTIVES: Evaluate the relationship between structural racism, nativity, PTB and SGA among US- and African-born Black women in California. METHODS: We conducted a population-based study of singleton births to US- and African-born Black women in California from 2011 to 2017 (n = 131,424). We examined the risk of PTB and SGA by nativity and neighbourhoods with differing levels of structural racism, as measured by the Index of Concentration at the Extremes. We fit crude and age-adjusted Poisson regression models, estimated using generalized estimating equations, with risk ratios (RR) and 95% confidence intervals (CI) as the effect measure. RESULTS: The proportions of PTB and SGA were 9.7% and 14.5%, respectively, for US-born women, while 5.6% and 8.3% for African-born women. US-born women (n = 24,782; 20.8%) were more likely to live in neighbourhoods with high structural racism compared to African-born women (n = 1474; 11.6%). Structural racism was associated with an elevated risk of PTB (RR 1.19, 95% CI 1.12, 1.26) and SGA (RR 1.19, 95% CI 1.13, 1.25) for all Black women, however, there was heterogeneity by nativity, with US-born women experiencing a higher magnitude of effect than African-born women. CONCLUSIONS: Among Black women in California, exposure to structural racism and the impacts of structural racism on the risk of PTB and SGA varied by nativity.

The Association of Gestational Age and Size with Management Strategies and Outcomes in Symptomatic Neonatal Tetralogy of Fallot.

 In neonatal, symptomatic tetralogy of Fallot (sTOF), data are lacking on whether high-risk groups would benefit from staged (SR) or complete repair (CR). We studied the association of gestational age (GA) at birth and z-score for birth weight (BWz), with management strategy and outcomes in sTOF. California population-based cohort study (2011-2017) of infants with sTOF (defined as catheter or surgical intervention prior to 44 weeks corrected GA) was performed, comparing management strategy and timing by GA and BWz categories. Multivariable models evaluated composite outcomes and days alive and out of hospital (DAOOH) in the first year of life. Among 345 patients (SR = 194; CR = 151), management strategy did not differ by GA or BWz with complete repair defined as prior to 44 weeks corrected gestational age; however, did differ by GA with regard to complete/timely repair (defined as complete repair within first 30 days of life). Full-term and early-term neonates underwent CR 20 (95%CI: - 27.1, - 14.1; p < 0.001) and 15 days (95%CI: - 22.1, - 8.2; p < 0.001) sooner than preterm neonates. Prematurity and major anomaly were associated with mortality or non-cardiac morbidity, while only major anomaly was associated with mortality or cardiac morbidity (OR = 3.5, 95%CI: 1.8,6.7, p < .0001). Full-term infants had greater DAOOH compared to preterm infants (35.2 days, 95%CI: 4.0, 66.5, p = 0.03). LGA infants and those with major anomaly had significantly lower DAOOH. In sTOF, patient specific risk factors such as prematurity and major anomaly were more associated with outcomes than management strategy.

Racial Disparities in Cesarean Delivery Rates: Do Hospital-Level Factors Matter?

OBJECTIVE: This study aimed to assess whether racial disparities in nulliparous, term, singleton, vertex cesarean delivery rates vary among hospitals of different type (academic vs. nonacademic), setting (urban vs. rural), delivery volume, and patient population. STUDY DESIGN: This is a retrospective cohort study including singleton term vertex live births in nulliparous Black and non-Hispanic White birthing people in California between 2011 and 2017. Cesarean delivery rates were obtained using birth certificate data and International Classification of Diseases, 9th/10th Revision codes. Risk of cesarean delivery was compared among Black versus White birthing people by hospital type (academic, nonacademic), setting (rural, suburban, urban), volume (< 1,200, 1,200-2,300, 2,400-3,599, ≥3,600 deliveries annually), and patient population (proportion Black-serving). Federal Information Processing codes were used to designate hospital setting. Risks were calculated using univariable and multivariable logistic regression and adjusted for birthing person age, body mass index, medical comorbidities, gestational age, labor type (spontaneous vs. induction), and infant birthweight. RESULTS: The sample included 59,441 Black (cesarean delivery rate: 30.2%) and 363,624 White birthing people (cesarean delivery rate: 26.1%). Black birthing people were significantly more likely than White birthing people to have a cesarean delivery across nearly all hospital-level factors considered with adjusted relative risks ranging from 1.1 to 1.3. The only exception was rural settings in which the adjusted relative risk was 1.3 but did not reach statistical significance. CONCLUSION: Black-White disparities in nulliparous, term, singleton, vertex cesarean delivery rates were persistent across all hospital-level factors we considered: academic status, rurality, delivery volume, and patient population. Furthermore, disparities existed at roughly the same magnitude regardless of hospital characteristics. These global increased risks likely reflect structural inequities in care, which contribute to disparities in pregnancy-related morbidity and mortality. These data should encourage providers, hospital systems, and quality collaboratives to further investigate racial disparities in cesarean delivery rates and develop strategies for eliminating them. KEY POINTS: · Nulliparous Black birthing people are more likely than White to undergo cesarean delivery.. · This persists across hospitals of all academic status, rurality, delivery volume, and patient population.. · These findings likely reflect structural rather than institutional inequities in obstetric care..

Adverse live-born pregnancy outcomes among pregnant people with anorexia nervosa.

BACKGROUND: Previous findings related to the association of adverse pregnancy outcomes with anorexia nervosa are mixed. OBJECTIVE: This study aimed to investigate the association of adverse live-born pregnancy outcomes with anorexia nervosa using adjustment modeling accounting for confounding factors, and a mediation analysis addressing the contribution of underweight prepregnancy body mass index and gestational weight gain to those outcomes. STUDY DESIGN: The sample included California live-born singletons with births between 2007 and 2021. The administrative data set contained birth certificates linked to hospital discharge records. Anorexia nervosa diagnosis during pregnancy was obtained from International Classification of Diseases codes on hospital discharge records. Adverse pregnancy outcomes examined included gestational diabetes, gestational hypertension, preeclampsia, anemia, antepartum hemorrhage, premature rupture of membranes, premature labor, cesarean delivery, oligohydramnios, placenta previa, chorioamnionitis, placental abruption, severe maternal morbidity, small for gestational age, large for gestational age, low birthweight, and preterm birth (by timing and indication). Risk of each adverse outcome was calculated using Poisson regression models. Unadjusted risk of each adverse outcome was calculated, and then the risks were adjusted for demographic factors. The final adjusted model included demographic factors, anxiety, depression, substance use, and smoking. A mediation analysis was performed to estimate the excess risk of adverse outcomes mediated by underweight prepregnancy body mass index and gestational weight gain below the American College of Obstetricians and Gynecologists recommendation. RESULTS: The sample included 241 pregnant people with a diagnosis of anorexia nervosa and 6,418,236 pregnant people without an eating disorder diagnosis. An anorexia nervosa diagnosis during pregnancy was associated with many adverse pregnancy outcomes in unadjusted models (relative risks ranged from 1.65 [preeclampsia] to 3.56 [antepartum hemorrhage]) in comparison with people without an eating disorder diagnosis. In the final adjusted models, birthing people with an anorexia nervosa diagnosis were more likely to have anemia, preterm labor, oligohydramnios, severe maternal morbidity, a small for gestational age or low-birthweight infant, and preterm birth between 32 and 36 weeks with spontaneous preterm labor (adjusted relative risks ranged from 1.43 to 2.55). Underweight prepregnancy body mass index mediated 7.78% of the excess in preterm births and 18.00% of the excess in small for gestational age infants. Gestational weight gain below the recommendation mediated 38.89% of the excess in preterm births and 40.44% of the excess in low-birthweight infants. CONCLUSION: Anorexia nervosa diagnosis during pregnancy was associated with a number of clinically important adverse pregnancy outcomes in comparison with people without an eating disorder diagnosis. Adjusting for anxiety, depression, substance use, and smoking during pregnancy decreased this risk. A substantial percentage of the excess risk of adverse outcomes was mediated by an underweight prepregnancy body mass index, and an even larger proportion of excess risk was mediated by gestational weight gain below the recommendation. This information is important for clinicians to consider when caring for patients with anorexia nervosa. Considering and treating anorexia nervosa and comorbid conditions and counseling patients about mediating factors such as preconception weight and gestational weight gain may improve live-born pregnancy outcomes among people with anorexia nervosa.

Structural racism is associated with adverse postnatal outcomes among Black preterm infants.

BACKGROUND: Structural racism contributes to racial disparities in adverse perinatal outcomes. We sought to determine if structural racism is associated with adverse outcomes among Black preterm infants postnatally. METHODS: Observational cohort study of 13,321 Black birthing people who delivered preterm (gestational age 22-36 weeks) in California in 2011-2017 using a statewide birth cohort database and the American Community Survey. Racial and income segregation was quantified by the Index of Concentration at the Extremes (ICE) scores. Multivariable generalized estimating equations regression models were fit to test the association between ICE scores and adverse postnatal outcomes: frequent acute care visits, readmissions, and pre- and post-discharge death, adjusting for infant and birthing person characteristics and social factors. RESULTS: Black birthing people who delivered preterm in the least privileged ICE tertiles were more likely to have infants who experienced frequent acute care visits (crude risk ratio [cRR] 1.3 95% CI 1.2-1.4), readmissions (cRR 1.1 95% CI 1.0-1.2), and post-discharge death (cRR 1.9 95% CI 1.2-3.1) in their first year compared to those in the privileged tertile. Results did not differ significantly after adjusting for infant or birthing person characteristics. CONCLUSION: Structural racism contributes to adverse outcomes for Black preterm infants after hospital discharge. IMPACT STATEMENT: Structural racism, measured by racial and income segregation, was associated with adverse postnatal outcomes among Black preterm infants including frequent acute care visits, rehospitalizations, and death after hospital discharge. This study extends our understanding of the impact of structural racism on the health of Black preterm infants beyond the perinatal period and provides reinforcement to the concept of structural racism contributing to racial disparities in poor postnatal outcomes for preterm infants. Identifying structural racism as a primary cause of racial disparities in the postnatal period is necessary to prioritize and implement appropriate structural interventions to improve outcomes.

Estimating the effect of timing of earned income tax credit refunds on perinatal outcomes: a quasi-experimental study of California births.

BACKGROUND: The largest poverty alleviation program in the US is the earned income tax credit (EITC), providing $60 billion to over 25 million families annually. While research has shown positive impacts of EITC receipt in pregnancy, there is little evidence on whether the timing of receipt may lead to differences in pregnancy outcomes. We used a quasi-experimental difference-in-differences design, taking advantage of EITC tax disbursement each spring to examine whether trimester of receipt was associated with perinatal outcomes. METHODS: We conducted a difference-in-differences analysis of California linked birth certificate and hospital discharge records. The sample was drawn from the linked CA birth certificate and discharge records from 2007-2012 (N = 2,740,707). To predict eligibility, we created a probabilistic algorithm in the Panel Study of Income Dynamics and applied it to the CA data. Primary outcome measures included preterm birth, small-for-gestational age (SGA), gestational diabetes, and gestational hypertension/preeclampsia. RESULTS: Eligibility for EITC receipt during the third trimester was associated with a lower risk of preterm birth compared with preconception. Eligibility for receipt in the preconception period resulted in improved gestational hypertension and SGA. CONCLUSION: This analysis offers a novel method to impute EITC eligibility using a probabilistic algorithm in a data set with richer sociodemographic information relative to the clinical and administrative data sets from which outcomes are drawn. These results could be used to determine the optimal intervention time point for future income supplementation policies. Future work should examine frequent income supplementation such as the minimum wage or basic income programs.

Adverse Maternal Fetal Environment Partially Mediates Disparate Outcomes in Non-White Neonates with Major Congenital Heart Disease.

OBJECTIVE: To determine whether differential exposure to an adverse maternal fetal environment partially explains disparate outcomes in infants with major congenital heart disease (CHD). STUDY DESIGN: Retrospective cohort study utilizing a population-based administrative California database (2011-2017). Primary exposure: Race/ethnicity. Primary mediator: Adverse maternal fetal environment (evidence of maternal metabolic syndrome and/or maternal placental syndrome). OUTCOMES: Composite of 1-year mortality or severe morbidity and days alive out of hospital in the first year of life (DAOOH). Mediation analyses determined the percent contributions of mediators on pathways between race/ethnicity and outcomes after adjusting for CHD severity. RESULTS: Included were 2747 non-Hispanic White infants (reference group), 5244 Hispanic, and 625 non-Hispanic Black infants. Hispanic and non-Hispanic Black infants had a higher risk for composite outcome (crude OR: 1.18; crude OR: 1.25, respectively) and fewer DAOOH (-6 & -12 days, respectively). Compared with the reference group, Hispanic infants had higher maternal metabolic syndrome exposure (43% vs 28%, OR: 1.89), and non-Hispanic Black infants had higher maternal metabolic syndrome (44% vs 28%; OR: 1.97) and maternal placental syndrome exposure (18% vs 12%; OR, 1.66). Both maternal metabolic syndrome exposure (OR: 1.21) and maternal placental syndrome exposure (OR: 1.56) were related to composite outcome and fewer DAOOH (-25 & -16 days, respectively). Adverse maternal fetal environment explained 25% of the disparate relationship between non-Hispanic Black race and composite outcome and 18% of the disparate relationship between Hispanic ethnicity and composite outcome. Adverse maternal fetal environment explained 16% (non-Hispanic Black race) and 21% (Hispanic ethnicity) of the association with DAOOH. CONCLUSIONS: Increased exposure to adverse maternal fetal environment contributes to racial and ethnic disparities in major CHD outcomes.

Residential particulate matter, proximity to major roads, traffic density and traffic volume as risk factors for preterm birth in California.

BACKGROUND: While pollution from vehicle sources is an established risk factor for preterm birth, it is unclear whether distance of residence to the nearest major road or related measures like major road density represent useful measures for characterising risk. OBJECTIVE: To determine whether major road proximity measures (including distance to major road, major road density and traffic volume) are more useful risk factors for preterm birth than other established vehicle-related measures (including particulate matter <2.5 µm in diameter (PM2.5 ) and diesel particulate matter (diesel PM)). METHODS: This retrospective cohort study included 2.7 million births across the state of California from 2011-2017; each address at delivery was geocoded. Geocoding was used to calculate distance to the nearest major road, major road density within a 500 m radius and major road density weighted by truck volume. We measured associations with preterm birth using risk ratios adjusted for target demographic, clinical, socioeconomic and environmental covariates (aRRs). We compared these to the associations between preterm birth and PM2.5 and diesel PM by census tract of residence. RESULTS: Findings showed that whereas higher mean levels of PM2.5 and diesel PM by census tract were associated with a higher risk of preterm birth, living closer to roads or living in higher traffic density areas was not associated with higher risk. Residence in a census tract with a mean PM2.5 in the top quartile compared with the lowest quartile was associated with the highest observed risk of preterm birth (aRR 1.04, 95% CI 1.04, 1.05). CONCLUSIONS: Over a large geographical region with a diverse population, PM2.5 and diesel PM were associated with preterm birth, while measures of distance to major road were not, suggesting that these distance measures do not serve as a proxy for measures of particulate matter in the context of preterm birth.

Risk of early birth by body mass index in a propensity score-matched sample: A retrospective cohort study.

OBJECTIVE: Evaluate the risk of preterm (<37 weeks) or early term birth (37 or 38 weeks) by body mass index (BMI) in a propensity score-matched sample. DESIGN: Retrospective cohort analysis. SETTING: California, USA. POPULATION: Singleton live births from 2011-2017. METHODS: Propensity scores were calculated for BMI groups using maternal factors. A referent sample of women with a BMI between 18.5 and <25.0 kg/m2 was selected using exact propensity score matching. Risk ratios for preterm and early term birth were calculated. MAIN OUTCOME MEASURES: Early birth. RESULTS: Women with a BMI <18.5 kg/m2 were at elevated risk of birth of 28-31 weeks (relative risk [RR] 1.2, 95% CI 1.1-1.4), 32-36 weeks (RR 1.3, 95% CI 1.2-1.3), and 37 or 38 weeks (RR 1.1, 95% CI 1.1-1.1). Women with BMI ≥25.0 kg/m2 were at 1.2-1.4-times higher risk of a birth <28 weeks and were at reduced risk of a birth between 32 and 36 weeks (RR 0.8-0.9) and birth during the 37th or 38th week (RR 0.9). CONCLUSION: Women with a BMI <18.5 kg/m2 were at elevated risk of a preterm or early term birth. Women with BMI ≥25.0 kg/m2 were at elevated risk of a birth <28 weeks. Propensity score-matched women with BMI ≥30.0 kg/m2 were at decreased risk of a spontaneous preterm birth with intact membranes between 32 and 36 weeks, supporting the complexity of BMI as a risk factor for preterm birth. TWEETABLE ABSTRACT: Propensity score-matched women with BMI ≥30 kg/m2 were at decreased risk of a late spontaneous preterm birth.

Risk Factors for Dual Burden of Severe Maternal Morbidity and Preterm Birth by Insurance Type in California.

OBJECTIVES: Among childbearing women, insurance coverage determines degree of access to preventive and emergency care for maternal and infant health. Maternal-infant dyads with dual burden of severe maternal morbidity and preterm birth experience high physical and psychological morbidity, and the risk of dual burden varies by insurance type. We examined whether sociodemographic and perinatal risk factors of dual burden differed by insurance type. METHODS: We estimated relative risks of dual burden by maternal sociodemographic and perinatal characteristics in the 2007-2012 California birth cohort dataset stratified by insurance type and compared effects across insurance types using Wald Z-statistics. RESULTS: Dual burden ranged from 0.36% of privately insured births to 0.41% of uninsured births. Obstetric comorbidities, multiple gestation, parity, and birth mode conferred the largest risks across all insurance types, but effect magnitude differed. The adjusted relative risk of dual burden associated with preeclampsia superimposed on preexisting hypertension ranged from 9.1 (95% CI 7.6-10.9) for privately insured to 15.9 (95% CI 9.1-27.6) among uninsured. The adjusted relative risk of dual burden associated with cesarean birth ranged from 3.1 (95% CI 2.7-3.5) for women with Medi-Cal to 5.4 (95% CI 3.5-8.2) for women with other insurance among primiparas, and 7.0 (95% CI 6.0-8.3) to 19.4 (95% CI 10.3-36.3), respectively, among multiparas. CONCLUSIONS: Risk factors of dual burden differed by insurance type across sociodemographic and perinatal factors, suggesting that care quality may differ by insurance type. Attention to peripartum care access and care quality provided by insurance type is needed to improve maternal and neonatal health.

Interpregnancy Interval and Birth Outcomes: A Propensity Matching Study in the California Population.

INTRODUCTION: Previous studies that used traditional multivariable and sibling matched analyses to investigate interpregnancy interval (IPI) and birth outcomes have reached mixed conclusions about a minimum recommended IPI, raising concerns about confounding. Our objective was to isolate the contribution of interpregnancy interval to the risk for adverse birth outcomes using propensity score matching. METHODS: For this retrospective cohort study, data were drawn from a California Department of Health Care Access and Information database with linked vital records and hospital discharge records (2007-2012). We compared short IPIs of < 6, 6-11, and 12-17 months to a referent IPI of 18-23 months using 1:1 exact propensity score matching on 13 maternal sociodemographic and clinical factors. We used logistic regression to calculate the odds of preterm birth, early-term birth, and small for gestational age (SGA). RESULTS: Of 144,733 women, 73.6% had IPIs < 18 months, 5.5% delivered preterm, 27.0% delivered early-term, and 6.0% had SGA infants. In the propensity matched sample (n = 83,788), odds of preterm birth were increased among women with IPI < 6 and 6-11 months (OR 1.89, 95% CI 1.71-2.0; OR 1.22, 95% CI 1.13-1.31, respectively) and not with IPI 12-17 months (OR 1.01, 95% CI 0.94-1.09); a similar pattern emerged for early-term birth. The odds of SGA were slightly elevated only for intervals < 6 months (OR 1.10, 95% CI 1.00-1.20, p < .05). DISCUSSION: This study demonstrates a dose response association between short IPI and adverse birth outcomes, with no increased risk beyond 12 months. Findings suggest that longer IPI recommendations may be overly proscriptive.

Association of Maternal Immune Activation during Pregnancy and Neurologic Outcomes in Offspring.

OBJECTIVE: To evaluate neurologic morbidity among offspring during their first year of life in association with prenatal maternal immune activation (MIA), using an inclusive definition. STUDY DESIGN: This retrospective cohort study included singletons born in California between 2011 and 2017. MIA was defined by International Classification of Diseases diagnosis of infection, autoimmune disorder, allergy, asthma, atherosclerosis, or malignancy during pregnancy. Neurologic morbidity in infants was defined by International Classification of Diseases diagnosis of intraventricular hemorrhage, periventricular leukomalacia, seizures, abnormal neurologic examination, or abnormal neurologic imaging. Outcomes of delayed developmental milestones during the first year of life were also explored. Risk of neurologic morbidity in offspring was approximated for women with and without MIA using log link binary regression. RESULTS: Demographic characteristics among 3 004 166 mother-infant dyads with or without MIA were similar in both groups. Rate of preterm delivery in mothers with MIA (9.4%) was significantly higher than those without MIA (5.6%). Infants of mothers with MIA were more likely to experience neurologic morbidities across all gestational ages. Adjusted relative risk (95% CI) in the exposed infants was 2.0 (1.9-2.1) for abnormal neurologic examination; 1.6 (1.5-1.7) for seizures, and 1.6 (1.4-1.8) for periventricular leukomalacia. CONCLUSIONS: Our results demonstrate that MIA during pregnancy may be associated with considerably higher risk of neurologic morbidity in offspring.

Mortality and Major Neonatal Morbidity in Preterm Infants with Serious Congenital Heart Disease.

OBJECTIVE: To investigate the trends of 1-year mortality and neonatal morbidities in preterm infants with serious congenital heart disease (CHD). STUDY DESIGN: This cohort study used a population-based administrative dataset of all liveborn infants of 26-36 weeks gestational age with serious CHD born in California between 2011 and 2017. We assessed 1-year mortality and major neonatal morbidities (ie, retinopathy of prematurity, bronchopulmonary dysplasia, necrotizing enterocolitis, intraventricular hemorrhage grade >2, and periventricular leukomalacia) across the study period and compared these outcomes with those in infants without CHD. RESULTS: We identified 1921 preterm infants with serious CHD. The relative risk (RR) of death decreased by 10.6% for each year of the study period (RR, 0.89; 95% CI, 0.84-0.95), and the RR of major neonatal morbidity increased by 8.3% for each year (RR, 1.08; 95% CI, 1.02-1.15). Compared with preterm neonates without any CHD (n = 234 522), the adjusted risk difference (ARD) for mortality was highest at 32 weeks of gestational age (9.7%; 95% CI, 8.3%-11.2%), that for major neonatal morbidity was highest at 28 weeks (21.9%; 95% CI, 17.0%-26.9%), and that for the combined outcome was highest at 30 weeks (26.7%; 95% CI, 23.3%-30.1%). CONCLUSIONS: Mortality in preterm neonates with serious CHD decreased over the last decade, whereas major neonatal morbidities increased. Preterm infants with a gestational age of 28-32 weeks have the highest mortality or morbidity compared with their peers without CHD. These results support the need for specialized and focused medical neonatal care in preterm neonates with serious CHD.

Newborn metabolic vulnerability profile identifies preterm infants at risk for mortality and morbidity.

BACKGROUND: Identifying preterm infants at risk for mortality or major morbidity traditionally relies on gestational age, birth weight, and other clinical characteristics that offer underwhelming utility. We sought to determine whether a newborn metabolic vulnerability profile at birth can be used to evaluate risk for neonatal mortality and major morbidity in preterm infants. METHODS: This was a population-based retrospective cohort study of preterm infants born between 2005 and 2011 in California. We created a newborn metabolic vulnerability profile wherein maternal/infant characteristics along with routine newborn screening metabolites were evaluated for their association with neonatal mortality or major morbidity. RESULTS: Nine thousand six hundred and thirty-nine (9.2%) preterm infants experienced mortality or at least one complication. Six characteristics and 19 metabolites were included in the final metabolic vulnerability model. The model demonstrated exceptional performance for the composite outcome of mortality or any major morbidity (AUC 0.923 (95% CI: 0.917-0.929). Performance was maintained across mortality and morbidity subgroups (AUCs 0.893-0.979). CONCLUSIONS: Metabolites measured as part of routine newborn screening can be used to create a metabolic vulnerability profile. These findings lay the foundation for targeted clinical monitoring and further investigation of biological pathways that may increase the risk of neonatal death or major complications in infants born preterm. IMPACT: We built a newborn metabolic vulnerability profile that could identify preterm infants at risk for major morbidity and mortality. Identifying high-risk infants by this method is novel to the field and outperforms models currently in use that rely primarily on infant characteristics. Utilizing the newborn metabolic vulnerability profile for precision clinical monitoring and targeted investigation of etiologic pathways could lead to reductions in the incidence and severity of major morbidities associated with preterm birth.

Twin chorionicity and zygosity both vary with maternal age.

Objective: To determine the ratio of dichorionic (DC) to monochorionic (MC) twins by maternal age. Methods: We reviewed all twin pregnancies undergoing first trimester screening (FTS) with nuchal translucency from April 2009 to December 2012 with sonographic determination of chorionicity. Cases were linked to newborn screening (NBS) results and zygosity estimated based on rates of fetal sex discordance. The ratio of DC to MC placentation by maternal age was calculated. Results: We identified 11,351 twin pregnancies with FTS and documented chorionicity. Among these, 7,861 (64.2%) had linked data on FTS and NBS to allow estimation of zygosity based on neonatal sex. Of these, 1,464 (18.6%) were MC and 6,406 (81.4%) DC. The MC twin rate remained constant while the DC twin rate increased with maternal age until 40y. At < 20y, 55% of twin pregnancies were monozygotic (MZ), as compared to 29% at ≥ 40y. Of MZ twins, 38% were DC at < 20y, while 53% were DC at ≥ 40y. Conclusions: Our data suggest a relationship of both zygosity and chorionicity with maternal age. DZ twinning increased with maternal age, while among MZ twins, the proportion that were DC also increased with maternal age.

Racial Disparities in the Rates of and Indications for Cesarean Delivery in California: Are They Changing Over Time?

OBJECTIVE: The aim of this study was to assess whether racial disparities in rates of and indications for cesarean delivery (CD) between non-Hispanic Black and non-Hispanic White birthing people in California changed from 2011 to 2017. METHODS: This was a retrospective cohort study using a database of birth certificates linked to discharge records. Singleton term live births in nulliparous Black and White birthing people in California between 2011 and 2017 were included. Those with noncephalic presentation, placenta previa, and placenta accreta were excluded. CD rate and indication were obtained from birth certificate variables and International Classification of Diseases codes. Differences in CD rate and indication were calculated for Black versus White individuals using univariable and multivariable logistic regression and adjusted for potential confounders. RESULTS: A total of 348,144 birthing people were included, 46,361 Black and 301,783 White. Overall, 30.9% of Black birthing people underwent CD compared with 25.3% of White (adjusted relative risk [aRR]: 1.2, 95% confidence interval [CI]: 1.2-1.3). From 2011 to 2017, the CD rate fell 11% (26.4-23.7%, p < 0.0001) for White birthing people and 1% for Black birthing people (30.4-30.1%, p = 0.037). Over the study period, Black birthing people had a persistent 1.2- to 1.3-fold higher risk of CD and were persistently more likely to undergo CD for fetal intolerance (aRR: 1.1, 95% CI: 1.1-1.2) and less likely for active phase arrest or arrest of descent (aRRs: 0.9 and 0.4; 95% CIs: 0.9-0.9 and 0.3-0.5). CONCLUSION: The CD rate decreased substantially for White birthing people and minimally for Black birthing people in our cohort over the study period. Meanwhile, disparities in CD rate and indications between the two groups persisted, despite controlling for confounders. Although care bundles for reducing CD may be effective among White birthing people, they are not associated with reduction in CD rates among Black birthing people nor improvements in racial disparities between Black and White birthing people. PRECIS: Despite increasing attention to racial inequities in obstetric outcomes, there were no changes in disparities in CD rates or indications in California from 2011 to 2017. KEY POINTS: · Black birthing people are more likely to undergo CD than White despite controlling for confounders.. · There are unexplained differences in CD indication among Black and White birthing people.. · These disparities persisted from 2011 to 2017 despite increasing efforts to decrease CD rates in CA..

Cohort study of respiratory hospital admissions, air quality and sociodemographic factors in preterm infants born in California.

BACKGROUND: Preterm infants suffer from respiratory morbidity especially during the first year of life. OBJECTIVE: To investigate the association of air quality and sociodemographic indicators on hospital admission rates for respiratory causes. METHODS: This is a retrospective cohort study. We identified all live-born preterm infants in California from 2007 to 2012 in a population-based administrative data set and linked them to a data set measuring several air quality and sociodemographic indicators at the census tract level. All sociodemographic and air quality predictors were divided into quartiles (first quartile most favourable to the fourth quartile least favourable). Mixed effect logistic models to account for clustering at the census tract level were used to investigate associations between chronic air quality and sociodemographic indicators respiratory hospital admission during the first year of life. RESULTS: Of 205 178 preterm infants, 5.9% (n = 12 033) were admitted to the hospital for respiratory causes during the first year. In the univariate analysis, comparing the first to the fourth quartile of chronic ozone (risk ratio [RR] 1.29, 95% confidence interval [CI] 1.21, 1.37), diesel (RR 1.10, 95% CI 1.02, 1.17) and particulate matter 2.5 (RR 1.07, 95% CI 1.01, 1.14) exposure were associated with hospital admission during the first year. Following adjustment for confounders, the risk ratios for hospital admission during the first year were 1.53 (95% CI 1.37, 1.72) in relation to educational attainment (per cent of the population over age 25 with less than a high school education) and 1.23 (95% CI 1.09, 1.38) for poverty (per cent of the population living below two times the federal poverty level). CONCLUSIONS: Among preterm infants, respiratory hospital admissions in the first year in California are associated with socioeconomic characteristics of the neighbourhood an individual is living in.

Preterm birth and nativity among Black women with gestational diabetes in California, 2013-2017: a population-based retrospective cohort study.

BACKGROUND: Despite the disproportionate prevalence of gestational diabetes (GDM) and preterm birth (PTB) and their associated adverse perinatal outcomes among Black women, little is known about PTB among Black women with GDM. Specifically, the relationship between PTB by subtype (defined as indicated PTB and spontaneous PT labor) and severity, GDM, and nativity has not been well characterized. Here we examine the risk of PTB by severity (early < 34 weeks, late 34 to 36 weeks) and early term birth (37 to 38 weeks) by nativity among Black women with GDM in California. METHODS: This retrospective cohort study used linked birth certificate and hospital discharge data for 8609 of the 100,691 self-identifying non-Hispanic Black women with GDM who had a singleton live birth between 20 and 44 weeks gestation in California in 2013-2017. Adjusted odds ratios (aOR) and 95% confidence intervals (CIs) were examine risks for PTB, by severity and subtype, and early term birth using multivariate regression modeling. RESULTS: Approximately, 83.9% of Black women with GDM were US-born and 16.1% were foreign-born. The overall prevalence of early PTB, late PTB, and early term birth was 3.8, 9.5, and 29.9%, respectively. Excluding history of prior PTB, preeclampsia was the greatest overall risk factor for early PTB (cOR = 6.7, 95%, CI 5.3 to 8.3), late PTB (cOR = 4.3, 95%, CI 3.8 to 5.0), and early term birth (cOR = 1.8, 95%, CI 1.6 to 2.0). There was no significant difference in the prevalence of PTB by subtypes and nativity (p = 0.5963). Overall, 14.2% of US- compared to 8.9% of foreign-born women had a PTB (early PTB: aOR = 0.56, 95%, CI 0.38 to 0.82; late PTB: aOR = 0.57, 95%, CI 0.45 to 0.73; early term birth: aOR = 0.67, 95%, CI 0.58 to 0.77). CONCLUSIONS: Foreign-born status remained protective of PTB, irrespective of severity and subtype. Preeclampsia, PTB, and GDM share pathophysiologic mechanisms suggesting a need to better understand differences in perinatal stress, chronic disease, and vascular dysfunction based on nativity in future epidemiologic studies and health services research.