Factors Associated with Maternal Morbidity among Black Women in the United States.

OBJECTIVE: Non-Hispanic Black people (NHBP) have a three-fold higher rate of maternal mortality compared to other racial groups. Racial disparities in maternal morbidity are well-described; however, there are substantial differences in cultural, economic, and social determinants of health among racial groups. We thus sought to study the at-risk, non-Hispanic Black population as its own cohort to identify factors most associated with severe maternal morbidity (SMM). STUDY DESIGN: This is a population-based retrospective case-control study of all live births in the United States between 2017 and 2019 using birth records obtained from the National Center for Health Statistics. The primary outcome for this study was to determine demographic, social, medical, and obstetric factors associated with maternal morbidity among NHBP who did and did not experience an SMM event. Multivariable logistic regression was used to estimate the adjusted odds ratio between each individual factor and the outcome of SMM among NHBP. RESULTS: Of the 1,624,744 NHBP who delivered between 2017 and 2019, 1.1% experienced an SMM event defined as a composite of blood product transfusion, eclamptic seizure, intensive care unit admission, unplanned hysterectomy, and uterine rupture. The rates of these individual SMM events per 10,000 deliveries were 50, 40, 20, 5, and 4 among NHBP, respectively. Among NHBP, factors associated in multivariable regression analysis with SMM in order of strength of association included cesarean delivery, earlier gestational age at delivery, preeclampsia, induction of labor, chronic hypertension, prior preterm birth, lower educational attainment, multifetal gestation, advanced maternal age, pregestational diabetes, and cigarette smoking. The population attributable fraction for cesarean delivery, preterm birth, and pregnancy-induced hypertensive disease for the outcome of SMM were 0.46, 0.23, and 0.07, respectively. CONCLUSION: The three factors most associated with SMM among NHBP are potentially avoidable or modifiable by aggressive screening, prevention, and treatment of preeclampsia and preterm birth as well as reducing cesarean rates in this population. KEY POINTS: · The rate of SMM in NHBP may be modifiable.. · NHBP have a three-fold higher rate of maternal mortality.. · Preeclampsia, preterm birth, and cesarean sections are most associated with maternal morbidity..

Exposure to airborne particulate matter during pregnancy is associated with preterm birth: a population-based cohort study.

BACKGROUND: Test the hypothesis that exposure to fine particulate matter in the air (PM2.5) is associated with increased risk of preterm birth (PTB). METHODS: Geo-spatial population-based cohort study using live birth records from Ohio (2007-2010) linked to average daily measures of PM2.5, recorded by 57 EPA network monitoring stations across the state. Geographic coordinates of the home residence for births were linked to the nearest monitoring station using ArcGIS. Association between PTB and high PM2.5 levels (above the EPA annual standard of 15 µg/m(3)) was estimated using GEE, with adjustment for age, race, education, parity, insurance, tobacco, birth season and year, and infant gender. An exchangeable correlation matrix for the monitor stations was used in the models. Analyses were limited to non-anomalous singleton births at 20-42weeks with no known chromosome abnormality occurring within 10 km of a monitor station. RESULTS: The frequency of PTB was 8.5 % in the study cohort of 224,921 singleton live births. High PM2.5 exposure (>EPA recommended maximum) occurred frequently during the study period, with 24,662 women (11 %) having high exposure in all three trimesters. Pregnancies with high PM2.5 exposure through pregnancy had increased PTB risk even after adjustment for coexisting risk factors, adjOR 1.19 (95 % CI 1.09-1.30). Assessed per trimester, high 3(rd) trimester PM2.5 exposure resulted in the highest PTB risk, adjOR 1.28 (95 % CI 1.20-1.37). CONCLUSIONS: Exposure to high levels of particulate air pollution, PM2.5, in pregnancy is associated with a 19 % increased risk of PTB; with greatest risk with high 3(rd) trimester exposure. Although the risk increase associated with high PM2.5 levels is modest, the potential impact on overall PTB rates is robust as all pregnant women are potentially at risk. This exposure may in part contribute to the higher preterm birth rates in Ohio compared to other states in the US, especially in urban areas.