Socioeconomic disadvantage and racial/ethnic disparities in low-risk cesarean birth in California.

Our objective was to assess the relationship of socioeconomic disadvantage and race/ethnicity with low-risk cesarean birth. We examined birth certificates (2007-18) linked with maternal hospitalization data from California; the outcome was cesarean birth among low-risk deliveries (i.e., nulliparous, term, singleton, vertex [NTSV]). We used GEE Poisson regression with an interaction term for race/ethnicity (7 groups) and a measure of socioeconomic disadvantage (census tract-level neighborhood deprivation index [NDI], education, or insurance). Among 1,815,933 NTSV births, 26.6% were cesarean. When assessing the joint effect of race/ethnicity and socioeconomic disadvantage among low-risk births, risk of cesarean birth increased with socioeconomic disadvantage for most racial/ethnic groups, and disadvantaged Black individuals had the highest risks; e.g., Black individuals with a high school education or less had a risk ratio of 1.49 (95% CI 1.45-1.53), relative to White individuals with a college degree. The disparity in risk of cesarean birth between Black and White individuals was observed across all strata of socioeconomic disadvantage. Asian American and Hispanic individuals had higher risks than White individuals at lower socioeconomic disadvantage; this disparity was not observed at higher levels of disadvantage. Black individuals have a persistent, elevated risk of cesarean birth, relative to White individuals, regardless of socioeconomic disadvantage.

Neighborhood-level Fatal Police Violence and Severe Maternal Morbidity in California.

Police violence is a pervasive issue that may have adverse implications for severe maternal morbidity (SMM). We assessed how the occurrence of fatal police violence (FPV) in one's neighborhood before/during pregnancy may influence SMM risk. Hospital discharge records from California between 2002-2018 were linked with the Fatal Encounters database (N=2,608,682). We identified 2,184 neighborhoods (census-tracts) with at least one FPV incident during the study period and used neighborhood fixed-effects models adjusting for individual sociodemographic characteristics to estimate odds of SMM associated with experiencing FPV in one's neighborhood anytime within the 24-months before childbirth. We did not find conclusive evidence on the link between FPV occurrence before delivery and SMM. However, estimates show that birthing people residing in neighborhoods where one or more FPV events had occurred within the preceding 24-months of giving birth may have a mildly elevated odds of SMM than those residing in the same neighborhoods with no FPV occurrence during the 24-months preceding childbirth (Odds Ratio (OR)=1.02; 95% Confidence Interval (CI): 0.99-1.05), particularly among those living in neighborhoods with fewer (1-2) FPV incidents throughout the study period (OR=1.03; 95% CI:1.00-1.06). Our findings provide evidence for the need to continue to examine the health consequences of police violence.

Trends and Disparities in Severe Maternal Morbidity Indicator Categories during Childbirth Hospitalization in California from 1997 to 2017.

OBJECTIVE: Severe maternal morbidity (SMM) is increasing and characterized by substantial racial and ethnic disparities. Analyzing trends and disparities across time by etiologic or organ system groups instead of an aggregated index may inform specific, actionable pathways to equitable care. We explored trends and racial and ethnic disparities in seven SMM categories at childbirth hospitalization. STUDY DESIGN: We analyzed California birth cohort data on all live and stillbirths ≥ 20 weeks' gestation from 1997 to 2017 (n = 10,580,096) using the Centers for Disease Control and Prevention's SMM index. Cases were categorized into seven nonmutually exclusive indicator categories (cardiac, renal, respiratory, hemorrhage, sepsis, other obstetric, and other medical SMM). We compared prevalence and trends in SMM indicator categories overall and by racial and ethnic group using logistic and linear regression. RESULTS: SMM occurred in 1.16% of births and nontransfusion SMM in 0.54%. Hemorrhage SMM occurred most frequently (27 per 10,000 births), followed by other obstetric (11), respiratory (7), and sepsis, cardiac, and renal SMM (5). Hemorrhage, renal, respiratory, and sepsis SMM increased over time for all racial and ethnic groups. The largest disparities were for Black individuals, including over 3-fold increased odds of other medical SMM. Renal and sepsis morbidity had the largest relative increases over time (717 and 544%). Sepsis and hemorrhage SMM had the largest absolute changes over time (17 per 10,000 increase). Disparities increased over time for respiratory SMM among Black, U.S.-born Hispanic, and non-U.S.-born Hispanic individuals and for sepsis SMM among Asian or Pacific Islander individuals. Disparities decreased over time for sepsis SMM among Black individuals yet remained substantial. CONCLUSION: Our research further supports the critical need to address SMM and disparities as a significant public health priority in the United States and suggests that examining SMM subgroups may reveal helpful nuance for understanding trends, disparities, and potential needs for intervention. KEY POINTS: · By SMM subgroup, trends and racial and ethnic disparities varied yet Black individuals consistently had highest rates.. · Hemorrhage, renal, respiratory, and sepsis SMM significantly increased over time.. · Disparities increased for respiratory SMM among Black, U.S.-born Hispanic and non-U.S.-born Hispanic individuals and for sepsis SMM among Asian or Pacific Islander individuals..

Postpartum Hospital Readmissions With and Without Severe Maternal Morbidity Within 1 Year of Birth, Oregon, 2012-2017.

Postpartum readmissions (PPRs) represent a critical marker of maternal morbidity after hospital childbirth. Most severe maternal morbidity (SMM) events result in a hospital admission, but most PPRs do not have evidence of SMM. Little is known about PPR and SMM beyond the first 6 weeks postpartum. We examined the associations of maternal demographic and clinical factors with PPR within 12 months postpartum. We categorized PPR as being with or without evidence of SMM to assess whether risk factors and timing differed. Using the Oregon All Payer All Claims database, we analyzed hospital births from 2012-2017. We used log-binomial regression to estimate associations between maternal factors and PPR. Our final analytical sample included 158,653 births. Overall, 2.6% (n = 4,141) of births involved at least 1 readmission within 12 months postpartum (808 (19.5% of PPRs) with SMM). SMM at delivery was the strongest risk factor for PPR with SMM (risk ratio (RR) = 5.55, 95% confidence interval (CI): 4.14, 7.44). PPR without SMM had numerous risk factors, including any mental health diagnosis (RR = 2.10, 95% CI: 1.91, 2.30), chronic hypertension (RR = 2.17, 95% CI: 1.85, 2.55), and prepregnancy diabetes (RR = 2.85, 95% CI: 2.47, 3.30), all which were on par with SMM at delivery (RR = 1.89, 95% CI: 1.49, 2.40).

Neighborhood-level Socioeconomic Position During Early Pregnancy and Risk of Gastroschisis.

BACKGROUND: Neighborhood-level socioeconomic position has been shown to influence birth outcomes, including selected birth defects. This study examines the un derstudied association between neighborhood-level socioeconomic position during early pregnancy and the risk of gastroschisis, an abdominal birth defect of increasing prevalence. METHODS: We conducted a case-control study of 1,269 gastroschisis cases and 10,217 controls using data from the National Birth Defects Prevention Study (1997-2011). To characterize neighborhood-level socioeconomic position, we conducted a principal component analysis to construct two indices-Neighborhood Deprivation Index (NDI) and Neighborhood Socioeconomic Position Index (nSEPI). We created neighborhood-level indices using census socioeconomic indicators corresponding to census tracts associated with addresses where mothers lived the longest during the periconceptional period. We used generalized estimating equations to estimate odds ratios (ORs) and 95% confidence intervals (CIs), with multiple imputations for missing data and adjustment for maternal race-ethnicity, household income, education, birth year, and duration of residence. RESULTS: Mothers residing in moderate (NDI Tertile 2 aOR = 1.23; 95% CI = 1.03, 1.48 and nSEPI Tertile 2 aOR = 1.24; 95% CI = 1.04, 1.49) or low socioeconomic neighborhoods (NDI Tertile 3 aOR = 1.28; 95% CI = 1.05, 1.55 and nSEPI Tertile 3 aOR = 1.32, 95% CI = 1.09, 1.61) were more likely to deliver an infant with gastroschisis compared with mothers residing in high socioeconomic neighborhoods. CONCLUSIONS: Our findings suggest that lower neighborhood-level socioeconomic position during early pregnancy is associated with elevated odds of gastroschisis. Additional epidemiologic studies may aid in confirming this finding and evaluating potential mechanisms linking neighborhood-level socioeconomic factors and gastroschisis.

Neighborhood Deprivation and Neural Tube Defects.

BACKGROUND: Individual measures of socioeconomic status (SES) have been associated with an increased risk of neural tube defects (NTDs); however, the association between neighborhood SES and NTD risk is unknown. Using data from the National Birth Defects Prevention Study (NBDPS) from 1997 to 2011, we investigated the association between measures of census tract SES and NTD risk. METHODS: The study population included 10,028 controls and 1829 NTD cases. We linked maternal addresses to census tract SES measures and used these measures to calculate the neighborhood deprivation index. We used generalized estimating equations to calculate adjusted odds ratios (aORs) and 95% confidence intervals (CIs) estimating the impact of quartiles of census tract deprivation on NTDs adjusting for maternal race-ethnicity, maternal education, and maternal age at delivery. RESULTS: Quartiles of higher neighborhood deprivation were associated with NTDs when compared with the least deprived quartile (Q2: aOR = 1.2; 95% CI = 1.0, 1.4; Q3: aOR = 1.3, 95% CI = 1.1, 1.5; Q4 (highest): aOR = 1.2; 95% CI = 1.0, 1.4). Results for spina bifida were similar; however, estimates for anencephaly and encephalocele were attenuated. Associations differed by maternal race-ethnicity. CONCLUSIONS: Our findings suggest that residing in a census tract with more socioeconomic deprivation is associated with an increased risk for NTDs, specifically spina bifida.

Exome-wide assessment of isolated biliary atresia: A report from the National Birth Defects Prevention Study using child-parent trios and a case-control design to identify novel rare variants.

The etiology of biliary atresia (BA) is unknown, but recent studies suggest a role for rare protein-altering variants (PAVs). Exome sequencing data from the National Birth Defects Prevention Study on 54 child-parent trios, one child-mother duo, and 1513 parents of children with other birth defects were analyzed. Most (91%) cases were isolated BA. We performed (1) a trio-based analysis to identify rare de novo, homozygous, and compound heterozygous PAVs and (2) a case-control analysis using a sequence kernel-based association test to identify genes enriched with rare PAVs. While we replicated previous findings on PKD1L1, our results do not suggest that recurrent de novo PAVs play important roles in BA susceptibility. In fact, our finding in NOTCH2, a disease gene associated with Alagille syndrome, highlights the difficulty in BA diagnosis. Notably, IFRD2 has been implicated in other gastrointestinal conditions and warrants additional study. Overall, our findings strengthen the hypothesis that the etiology of BA is complex.

Remapping racial and ethnic inequities in severe maternal morbidity: The legacy of redlining in California.

BACKGROUND: Historical mortgage redlining, a racially discriminatory policy designed to uphold structural racism, may have played a role in producing the persistently elevated rate of severe maternal morbidity (SMM) among racialised birthing people. OBJECTIVE: This study examined associations between Home-Owner Loan Corporation (HOLC) redlining grades and SMM in a racially and ethnically diverse birth cohort in California. METHODS: We leveraged a population-based cohort of all live hospital births at ≥20 weeks of gestation between 1997 and 2017 in California. SMM was defined as having one of 21 procedures and diagnoses, per an index developed by Centers for Disease Control and Prevention. We characterised census tract-level redlining using HOLC's security maps for eight California cities. We assessed bivariate associations between HOLC grades and participant characteristics. Race and ethnicity-stratified mixed effects logistic regression models assessed the risk of SMM associated with HOLC grades within non-Hispanic Black, Asian/Pacific Islander, American Indian/Alaskan Native and Hispanic groups, adjusting for sociodemographic information, pregnancy-related factors, co-morbidities and neighbourhood deprivation index. RESULTS: The study sample included 2,020,194 births, with 24,579 cases of SMM (1.2%). Living in a census tract that was graded as "Hazardous," compared to census tracts graded "Best" and "Still Desirable," was associated with 1.15 (95% confidence interval [CI] 1.03, 1.29) and 1.17 (95% CI 1.09, 1.25) times the risk of SMM among Black and Hispanic birthing people, respectively, independent of sociodemographic factors. These associations persisted after adjusting for pregnancy-related factors and neighbourhood deprivation index. CONCLUSIONS: Historical redlining, a tool of structural racism that influenced the trajectory of neighbourhood social and material conditions, is associated with increased risk of experiencing SMM among Black and Hispanic birthing people in California. These findings demonstrate that addressing the enduring impact of macro-level and systemic mechanisms that uphold structural racism is a vital step in achieving racial and ethnic equity in birthing people's health.

Assessing associations between residential proximity to greenspace and birth defects in the National Birth Defects Prevention Study.

BACKGROUND: Residential proximity to greenspace is associated with various health outcomes. OBJECTIVES: We estimated associations between maternal residential proximity to greenspace (based on an index of vegetation) and selected structural birth defects, including effect modification by neighborhood-level factors. METHODS: Data were from the National Birth Defects Prevention Study (1997-2011) and included 19,065 infants with at least one eligible birth defect (cases) and 8925 without birth defects (controls) from eight Centers throughout the United States. Maternal participants reported their addresses throughout pregnancy. Each address was systematically geocoded and residences around conception were linked to greenspace, US Census, and US Department of Agriculture data. Greenspace was estimated using the normalized difference vegetation index (NDVI); average maximum NDVI was estimated within 100 m and 500 m concentric buffers surrounding geocoded addresses to estimate residential NDVI. We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals comparing those in the highest and lowest quartiles of residential NDVI and stratifying by rural/urban residence and neighborhood median income. RESULTS: After multivariable adjustment, for the 500 m buffer, inverse associations were observed for tetralogy of Fallot, secundum atrial septal defects, anencephaly, anotia/microtia, cleft lip ± cleft palate, transverse limb deficiency, and omphalocele, (aORs: 0.54-0.86). Results were similar for 100 m buffer analyses and similar patterns were observed for other defects, though results were not significant. Significant heterogeneity was observed after stratification by rural/urban for hypoplastic left heart, coarctation of the aorta, and cleft palate, with inverse associations only among participants residing in rural areas. Stratification by median income showed heterogeneity for atrioventricular and secundum atrial septal defects, anencephaly, and anorectal atresia, with inverse associations only among participants residing in a high-income neighborhood (aORs: 0.45-0.81). DISCUSSION: Our results suggest that perinatal residential proximity to more greenspace may contribute to a reduced risk of certain birth defects, especially among those living in rural or high-income neighborhoods.

Factors Associated with Transfer Distance from Birth Hospital to Repair Hospital for First Surgical Repair among Infants with Myelomeningocele in California.

OBJECTIVE: The objective of our study was to examine factors associated with distance to care for first surgical repair among infants with myelomeningocele in California. STUDY DESIGN: A total of 677 eligible cases with complete geocoded data were identified for birth years 2006 to 2012 using data from the California Perinatal Quality Care Collaborative linked to hospital and vital records. The median distance from home to birth hospital among eligible infants was 9 miles, and from birth hospital to repair hospital was 15 miles. We limited our analysis to infants who lived close to the birth hospital, creating two study groups to examine transfer distance patterns: "lived close and had a short transfer" (i.e., lived <9 miles from birth hospital and traveled <15 miles from birth hospital to repair hospital; n = 92), and "lived close and had a long transfer" (i.e., lived <9 miles from birth hospital and traveled ≥15 miles from birth hospital to repair hospital; n = 96). Log-binomial regression was used to estimate crude and adjusted risk ratios (aRRs and 95% confidence intervals (CIs). Selected maternal, infant, and birth hospital characteristics were compared between the two groups. RESULTS: We found that low birth weight (aRR = 1.44; 95% CI = 1.04, 1.99) and preterm birth (aRR = 1.41; 95% CI = 1.01, 1.97) were positively associated, whereas initiating prenatal care early in the first trimester was inversely associated (aRR = 0.64; 95% CI = 0.46, 0.89) with transferring a longer distance (≥15 miles) from birth hospital to repair hospital. No significant associations were noted by maternal race-ethnicity, socioeconomic indicators, or the level of hospital care at the birth hospital. CONCLUSION: Our study identified selected infant factors associated with the distance to access surgical care for infants with myelomeningocele who had to transfer from birth hospital to repair hospital. Distance-based barriers to care should be identified and optimized when planning deliveries of at-risk infants in other populations. KEY POINTS: · Low birth weight predicted long hospital transfer distance.. · Preterm birth was associated with transfer distance.. · Prenatal care was associated with transfer distance..

Early Postpartum Hospital Encounters among Patients with Genitourinary and Wound Infections during Hospitalization for Birth.

OBJECTIVES: This study aimed to assess the associations between genitourinary and wound infections during the birth hospitalization and early postpartum hospital encounters, and to evaluate clinical risk factors for early postpartum hospital encounters among patients with genitourinary and wound infections during the birth hospitalization. STUDY DESIGN: We conducted a population-based cohort study of births in California during 2016 to 2018 and postpartum hospital encounters. We identified genitourinary and wound infections using diagnosis codes. Our main outcome was early postpartum hospital encounter, defined as a readmission or emergency department (ED) visit within 3 days after discharge from the birth hospitalization. We evaluated the association of genitourinary and wound infections (overall and subtypes) with early postpartum hospital encounter using logistic regression, adjusting for sociodemographic factors and comorbidities and stratified by mode of birth. We then evaluated factors associated with early postpartum hospital encounter among patients with genitourinary and wound infections. RESULTS: Among 1,217,803 birth hospitalizations, 5.5% were complicated by genitourinary and wound infections. Genitourinary or wound infection was associated with an early postpartum hospital encounter among patients with both vaginal births (2.2%; adjusted risk ratio [aRR[: 1.26; 95% confidence interval [CI]: 1.17-1.36) and cesarean births (3.2%; aRR: 1.23; 95% CI: 1.15-1.32). Patients with a cesarean birth and a major puerperal infection or wound infection had the highest risk of an early postpartum hospital encounter (6.4 and 4.3%, respectively). Among patients with genitourinary and wound infections during the birth hospitalization, factors associated with an early postpartum hospital encounter included severe maternal morbidity, major mental health condition, prolonged postpartum hospital stay, and, among cesarean births, postpartum hemorrhage (p-value < 0.05). CONCLUSION: Genitourinary and wound infections during hospitalization for birth may increase risk of a readmission or ED visit within the first few days after discharge, particularly among patients who have a cesarean birth and a major puerperal infection or wound infection. KEY POINTS: · In all, 5.5% of patients giving birth had a genitourinary or wound infection (GWI).. · A total of 2.7% of GWI patients had a hospital encounter within 3 days of discharge after birth.. · Major puerperal infection and wound infection had the highest risk of an early hospital encounter.. · Among GWI patients, several birth complications were associated with an early hospital encounter..

Subsequent risk of stillbirth, preterm birth, and small for gestational age: A cross-outcome analysis of adverse birth outcomes.

BACKGROUND: Stillbirth, preterm birth, and small for gestational age (SGA) birth have an increased recurrence risk. The occurrence of one of these biologically related outcomes could also increase the risk for another one of these outcomes in a subsequent pregnancy. OBJECTIVES: We assessed cross-outcome risks for subsequent stillbirth, preterm birth, and SGA. METHODS: We used live birth and fetal death records to identify singleton, sequential birth pairs in California (1997-2017). Stillbirth was defined as delivery at ≥20 weeks of gestation of a foetus that died in utero; preterm birth as live birth at 20-36 weeks; and small for gestational age as sex-specific birthweight <10th percentile for gestational age. Risk ratios (RR) were computed using modified Poisson regression and adjusted for potential confounders. Sensitivity analyses included analysing a cohort restricted to primiparous index births and using inverse-probability censoring weights. RESULTS: Of 3,108,532 birth pairs, 16,668 (0.5%), 260,596 (8.4%) and 331,109 (10.7%) of index births were stillborn, preterm and SGA, respectively. Among individuals with an index stillbirth, the adjusted RRs were 1.90 (95% confidence interval [CI] 1.83, 1.98) for subsequent preterm and 1.35 (95% CI 1.28, 1.41) for subsequent SGA. Among those with index preterm birth, the adjusted RRs were 2.02 (95% CI 1.92, 2.13) for stillbirth and 1.42 (95% CI 1.41, 1.44) for SGA. Among those with index SGA, the adjusted RRs were 1.54 (95% CI 1.46, 1.63) for stillbirth and 1.45 (95% CI 1.44, 1.47) for preterm birth. Similar results were reported for sensitivity analyses. CONCLUSIONS: Individuals experiencing stillbirth, preterm birth, or SGA in one pregnancy had an increased risk of one of these biologically related outcomes in a subsequent pregnancy. These findings could encourage enhanced surveillance for individuals who experience stillbirth, preterm birth, or SGA and desire a subsequent pregnancy.

Antihypertensive Medication Use before and during Pregnancy and the Risk of Severe Maternal Morbidity in Individuals with Prepregnancy Hypertension.

OBJECTIVE: Our objective is to examine severe maternal morbidity (SMM) and patterns of antihypertensive medication use before and during pregnancy among individuals with chronic hypertension. STUDY DESIGN: We examined 11,759 pregnancies resulting in a live birth or stillbirth to individuals with chronic hypertension and one or more antihypertensive prescription 6 months before pregnancy (Optum, 2007-17). We examined whether study outcomes were associated with the use of medication as compared to no use during pregnancy. In addition, patterns of medication use based on the Food and Drug Administration guidance and literature were evaluated. Medication use was divided into prepregnancy and during pregnancy use and classified as pregnancy recommended (PR) or not pregnancy recommended (nPR) or no medication use. SMM was defined per the Centers for Disease Control and Prevention definition of 21 indicators. Risk ratios (RR) reflecting the association of SMM with the use of antihypertensive medications were computed using modified Poisson regression with robust standard errors and adjusted for maternal age, education, and birth year. RESULTS: Overall, 83% of individuals filled an antihypertensive prescription during pregnancy and 6.3% experienced SMM. The majority of individuals with a prescription prior to pregnancy had a prescription for the same medication in pregnancy. Individuals with any versus no medication use in pregnancy had increased adjusted RR (aRR) of SMM (1.18, 95% confidence interval [CI]: 0.96-1.44). Compared to the use of PR medications before and during pregnancy, aRRs were 1.42 (95% CI: 1.18-1.69, 12.4% of sample) for nPR use before and during pregnancy, 1.52 (1.23-1.86; 12.4%) for nPR (before) and PR (during) use, and 2.67 (1.73-4.15) for PR and nPR use. Patterns with no medication use during pregnancy were not statistically significant. CONCLUSION: Pattern of antihypertensive medication use before and during pregnancy may be associated with an elevated risk of SMM. Further research is required to elucidate whether this association is related to the severity of hypertension, medication effectiveness, or suboptimal quality of care. KEY POINTS: · Individuals with any medication use compared to no medication use in pregnancy had an increased risk of SMM.. · Specific medication use patterns were associated with an elevated risk of SMM.. · Pattern of antihypertensive medication use before and during pregnancy may be associated with an increased risk of SMM..

Severe Maternal Morbidity: A Comparison of Definitions and Data Sources.

Severe maternal morbidity (SMM) is a composite outcome measure that indicates serious, potentially life-threatening maternal health problems. There is great interest in defining SMM using administrative data for surveillance and research. In the United States, one common way of defining SMM at the population level is an index developed by the Centers for Disease Control and Prevention. Modifications to this index (e.g., exclusion of maternal blood transfusion) have been proposed; some research defines SMM using an index introduced by Bateman et al. (Obstet Gynecol. 2013;122(5):957-965). Birth certificate data are also increasingly being used to define SMM. We compared commonly used US definitions of SMM among all California births (2007-2012) using the kappa (κ) statistic and other measures. We also evaluated agreement between maternal morbidity fields on the birth certificate as compared with health insurance claims data. Concordance between the 7 definitions of SMM analyzed was generally low (i.e., κ < 0.41 for 13 of 21 two-way comparisons). Low concordance was particularly driven by the presence/absence of transfusion and claims data versus birth certificate definitions. Low agreement between administrative data-based definitions of SMM highlights that results can be expected to differ between them. Further research on validity of SMM definitions, using more fine-grained data sources, is needed.

Interpregnancy Interval and Subsequent Severe Maternal Morbidity: A 16-Year Population-Based Study From California.

Interpregnancy interval (IPI) is associated with adverse perinatal outcomes, but its contribution to severe maternal morbidity (SMM) remains unclear. We examined the association between IPI and SMM, using data linked across sequential pregnancies to women in California during 1997-2012. Adjusting for confounders measured in the index pregnancy (i.e., the first in a pair of consecutive pregnancies), we estimated adjusted risk ratios for SMM related to the subsequent pregnancy. We further conducted within-mother comparisons and analyses stratified by parity and maternal age at the index pregnancy. Compared with an IPI of 18-23 months, an IPI of <6 months had the same risk for SMM in between-mother comparisons (adjusted risk ratio (aRR) = 0.96, 95% confidence interval (CI): 0.91, 1.02) but lower risk in within-mother comparisons (aRR = 0.76, 95% CI: 0.67, 0.86). IPIs of 24-59 months and ≥60 months were associated with increased risk of SMM in both between-mother (aRR = 1.18 (95% CI: 1.13, 1.23) and aRR = 1.76 (95% CI: 1.68, 1.85), respectively) and within-mother (aRR = 1.22 (95% CI: 1.11, 1.34) and aRR = 1.88 (95% CI: 1.66, 2.13), respectively) comparisons. The association between IPI and SMM did not vary substantially by maternal age or parity. In this study, longer IPI was associated with increased risk of SMM, which may be partly attributed to interpregnancy health.

Birth hospital and racial and ethnic differences in severe maternal morbidity in the state of California.

BACKGROUND: Birth hospital has recently emerged as a potential key contributor to disparities in severe maternal morbidity, but investigations on its contribution to racial and ethnic differences remain limited. OBJECTIVE: We leveraged statewide data from California to examine whether birth hospital explained racial and ethnic differences in severe maternal morbidity. STUDY DESIGN: This cohort study used data on all births at ≥20 weeks gestation in California (2007-2012). Severe maternal morbidity during birth hospitalization was measured using the Centers for Disease Control and Prevention index of having at least 1 of the 21 diagnoses and procedures (eg, eclampsia, blood transfusion, hysterectomy). Mixed-effects logistic regression models (ie, women nested within hospitals) were used to compare racial and ethnic differences in severe maternal morbidity before and after adjustment for maternal sociodemographic and pregnancy-related factors, comorbidities, and hospital characteristics. We also estimated the risk-standardized severe maternal morbidity rates for each hospital (N=245) and the percentage reduction in severe maternal morbidity if each group of racially and ethnically minoritized women gave birth at the same distribution of hospitals as non-Hispanic white women. RESULTS: Of the 3,020,525 women who gave birth, 39,192 (1.3%) had severe maternal morbidity (2.1% Black; 1.3% US-born Hispanic; 1.3% foreign-born Hispanic; 1.3% Asian and Pacific Islander; 1.1% white; 1.6% American Indian and Alaska Native, and Mixed-race referred to as Other). Risk-standardized rates of severe maternal morbidity ranged from 0.3 to 4.0 per 100 births across hospitals. After adjusting for covariates, the odds of severe maternal morbidity were greater among nonwhite women than white women in a given hospital (Black: odds ratio, 1.25; 95% confidence interval, 1.19-1.31); US-born Hispanic: odds ratio, 1.25; 95% confidence interval, 1.20-1.29; foreign-born Hispanic: odds ratio, 1.17; 95% confidence interval, 1.11-1.24; Asian and Pacific Islander: odds ratio, 1.26; 95% confidence interval, 1.21-1.32; Other: odds ratio, 1.31; 95% confidence interval, 1.15-1.50). Among the studied hospital factors, only teaching status was associated with severe maternal morbidity in fully adjusted models. Although 33% of white women delivered in hospitals with the highest tertile of severe maternal morbidity rates compared with 53% of Black women, birth hospital only accounted for 7.8% of the differences in severe maternal morbidity comparing Black and white women and accounted for 16.1% to 24.2% of the differences for all other racial and ethnic groups. CONCLUSION: In California, excess odds of severe maternal morbidity among racially and ethnically minoritized women were not fully explained by birth hospital. Structural causes of racial and ethnic disparities in severe maternal morbidity may vary by region, which warrants further examination to inform effective policies.

Recurrence of severe maternal morbidity: A population-based cohort analysis of California women.

BACKGROUND: Severe maternal morbidity (SMM) has increased in the United States by 45% in the last decade. While the recurrence of several adverse pregnancy outcomes from one pregnancy to the next has been established, the recurrence risk of SMM is unknown. OBJECTIVE: To determine whether women who have SMM in a first pregnancy are at increased risk of SMM in their second pregnancy, compared to women who did not have SMM in their first pregnancy. METHODS: This is a population-based study using linked vital statistics and hospital discharge records from the Office of Statewide Health Planning and Development in California from 1997 to 2012. The study population had their first two singleton births (live births or stillbirths) in California between 1997 and 2012 (n = 1 180 357). The primary exposure was SMM during the hospitalisation at first birth, and the primary outcome was SMM during the hospitalisation at second birth. Prevalence and risk ratios of SMM at second birth were computed for women who did and did not have SMM at first birth, as well as for certain specific indicators of SMM. RESULTS: Of the 1 180 357 women included in this analysis, 9088 (77 per 10 000 births) experienced SMM at first birth. Among these women, the prevalence of SMM at second birth was 470 per 10 000 births, compared to 68 per 10 000 births among women without SMM at first birth. This corresponded to an unadjusted risk ratio of 6.87 (95% CI 6.23, 7.57), which did not differ substantially when adjusted for factors known to be associated with SMM (6.42, 95% CI 5.86, 7.13). CONCLUSION: Women experiencing SMM in their first pregnancy were at an approximately sixfold increased risk of experiencing SMM in their second pregnancy.

Timing of Transfer and Mortality in Neonates with Hypoplastic Left Heart Syndrome in California.

Maternal race/ethnicity is associated with mortality in neonates with hypoplastic left heart syndrome (HLHS). We investigated whether maternal race/ethnicity and other sociodemographic factors affect timing of transfer after birth and whether timing of transfer impacts mortality in infants with HLHS. We linked two statewide databases, the California Perinatal Quality Care Collaborative and records from the Office of Statewide Health Planning and Development, to identify cases of HLHS born between 1/1/06 and 12/31/11. Cases were divided into three groups: birth at destination hospital, transfer on day of life 0-1 ("early transfer"), or transfer on day of life ≥ 2 ("late transfer"). We used log-binomial regression models to estimate relative risks (RR) for timing of transfer and Cox proportional hazard models to estimate hazard ratios (HR) for mortality. We excluded infants who died within 60 days of life without intervention from the main analyses of timing of transfer, since intervention may not have been planned in these infants. Of 556 cases, 107 died without intervention (19%) and another 52 (9%) died within 28 days. Of the 449 included in analyses of timing of transfer, 28% were born at the destination hospital, 49% were transferred early, and 23% were transferred late. Late transfer was more likely for infants of low birthweight (RR 1.74) and infants born to US-born Hispanic (RR 1.69) and black (RR 2.45) mothers. Low birthweight (HR 1.50), low 5-min Apgar score (HR 4.69), and the presence of other major congenital anomalies (HR 3.41), but not timing of transfer, predicted neonatal mortality. Late transfer was more likely in neonates born to US-born Hispanic and black mothers but was not associated with higher mortality.

Factors Associated with Early Neonatal and First-Year Mortality in Infants with Myelomeningocele in California from 2006 to 2011.

OBJECTIVE: The aim of this study is to examine factors associated with early neonatal (death within first 7 days of birth) and infant (death during the first year of life) mortality among infants born with myelomeningocele. STUDY DESIGN: We examined linked data from the California Perinatal Quality Care Collaborative, vital records, and hospital discharge records for infants born with myelomeningocele from 2006 to 2011. Survival probability was calculated using Kaplan-Meier Product Limit method and 95% confidence intervals (CI) using Greenwood's method; Cox proportional hazard models were used to estimate unadjusted and adjusted hazard ratios (HR) and 95% CI. RESULTS: Early neonatal and first-year survival probabilities among infants born with myelomeningocele were 96.0% (95% CI: 94.1-97.3%) and 94.5% (95% CI: 92.4-96.1%), respectively. Low birthweight and having multiple co-occurring birth defects were associated with increased HRs ranging between 5 and 20, while having congenital hydrocephalus and receiving hospital transfer from the birth hospital to another hospital for myelomeningocele surgery were associated with HRs indicating a protective association with early neonatal and infant mortality. CONCLUSION: Maternal race/ethnicity and social disadvantage did not predict early neonatal and infant mortality among infants with myelomeningocele; presence of congenital hydrocephalus and the role of hospital transfer for myelomeningocele repair should be further examined. KEY POINTS: · Mortality in myelomeningocele is a concern. · Social disadvantage was not associated with death. · Hospital-based factors should be further examined.

Pre-pregnancy Obesity and the Risk of Peripartum Cardiomyopathy.

OBJECTIVE: The aim of this study is to evaluate the contribution of pre-pregnancy obesity and overweight to peripartum cardiomyopathy. STUDY DESIGN: This population-based study used linked birth record and maternal hospital discharge data from live births in California during 2007 to 2012 (n = 2,548,380). All women who had a diagnosis of peripartum cardiomyopathy during the childbirth hospitalization or who were diagnosed with peripartum cardiomyopathy during a postpartum hospital readmission within 5 months of birth were identified as cases. Pre-pregnancy body mass index (BMI, kg/m2) was classified as normal weight (18.5-24.9), overweight (25.0-29.9), obesity class 1 (30.0-34.9), obesity class 2 (35.0-39.9), and obesity class 3 (≥40). Because of small numbers, we excluded women with underweight BMI, and in some analyses, we combined obesity classes into one group. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) expressing associations between BMI and peripartum cardiomyopathy, adjusted for maternal age, race/ethnicity, education, health care payer, parity, plurality, and comorbidities. RESULTS: The overall prevalence of peripartum cardiomyopathy during hospital admissions was 1.3 per 10,000 live births (n = 320). Unadjusted ORs were 1.32 (95% CI: 1.01-1.74) for women with overweight BMI and 2.03 (95% CI: 1.57-2.62) for women with obesity, compared with women with normal pre-pregnancy BMI. Adjusted ORs were 1.26 (95% CI: 0.95-1.66) for overweight women and 1.38 (95% CI: 1.04-1.84) for women with obesity. The ORs suggested a dose-response relationship with increasing levels of obesity, but the 95% CIs for the specific classes of obesity included 1.00. CONCLUSION: Pre-pregnancy obesity was associated with an increased risk of peripartum cardiomyopathy. These findings underscore the importance of BMI during pregnancy. There is a need to recognize the increased risk of peripartum cardiomyopathy in women with high BMI, especially in the late postpartum period. KEY POINTS: · Pre-pregnancy obesity affects maternal health.. · Effects may extend to peripartum cardiomyopathy.. · The risk includes peripartum cardiomyopathy that emerges postpartum..