Racial and Ethnic Disparities among Pregnancies with Chronic Hypertension and Adverse Outcomes

Objective We aimed to ascertain whether the risk of adverse pregnancy outcomes in the United States among individuals with chronic hypertension differed by maternal race and ethnicity and to assess the temporal trend.Study Design Population-based retrospective study using the U.S. Vital Statistics datasets evaluated pregnancies with chronic hypertension, singleton live births that delivered at 24 to 41 weeks. The coprimary outcomes were a composite maternal adverse outcome (preeclampsia, primary cesarean delivery, intensive care unit admission, blood transfusion, uterine rupture, or unplanned hysterectomy) and a composite neonatal adverse outcome (preterm birth, small for gestational age, Apgar's score < 5 at 5 minutes, assisted ventilation > 6 hours, seizure, or death). Multivariable Poisson regression models were used to estimate adjusted relative risks (aRRs) and 95% confidence intervals (CIs).Results Between 2014 and 2019, the rate of chronic hypertension in pregnancy increased from 1.6 to 2.2%. After multivariable adjustment, an increased risk for the composite maternal adverse outcome was found in Black (aRR = 1.10, 95% CI = 1.09-1.11), Hispanic (aRR = 1.04, 95% CI = 1.02-1.05), and Asian/Pacific Islander (aRR = 1.07, 95% CI = 1.05-1.10), compared with White individuals. Compared with White individuals, the risk of the composite neonatal adverse outcome was higher in Black (aRR = 1.39, 95% CI = 1.37-1.41), Hispanic (aRR = 1.15, 95% CI = 1.13-1.16), Asian/Pacific Islander (aRR = 1.34, 95% CI = 1.31-1.37), and American Indian (aRR = 1.12, 95% CI = 1.07-1.17). The racial and ethnic disparity remained unchanged during the study period.Conclusion We found a racial and ethnic disparity with maternal and neonatal adverse outcomes in pregnancies with chronic hypertension that remained unchanged throughout the study period.