Historical and Recent Changes in Maternal Mortality Due to Hypertensive Disorders in the United States, 1979 to 2018

Abstract

We evaluated the contributions of maternal age, year of death (period), and year of birth (cohort) on trends in hypertension-related maternal deaths in the United States. We undertook a sequential time series analysis of 155 710 441 live births and 3287 hypertension-related maternal deaths in the United States, 1979 to 2018. Trends in pregnancy-related mortality rate (maternal mortality rate [MMR]) due to chronic hypertension, gestational hypertension, and preeclampsia/eclampsia, were examined. MMR was defined as death during pregnancy or within 42 days postpartum due to hypertension. Trends in overall and race-specific hypertension-related MMR based on age, period, and birth cohort were evaluated based on weighted Poisson models. Trends were also adjusted for secular changes in obesity rates and corrected for potential death misclassification. During the 40-year period, the overall hypertension-related MMR was 2.1 per 100 000 live births, with MMR being almost 4-fold higher among Black compared with White women (5.4 [n=1396] versus 1.4 [n=1747] per 100 000 live births). Advancing age was associated with a sharp increase in MMR at ≥15 years among Black women and at ≥25 years among White women. Birth cohort was also associated with increasing MMR. Preeclampsia/eclampsia-related MMR declined annually by 2.6% (95% CI, 2.2–2.9), but chronic hypertension–related MMR increased annually by 9.2% (95% CI, 7.9–10.6). The decline in MMR was attenuated when adjusted for increasing obesity rates. The temporal burden of hypertension-related MMR in the United States has increased substantially for chronic hypertension–associated MMR and decreased for preeclampsia/eclampsia-associated MMR. Nevertheless, deaths from hypertension continue to contribute substantially to maternal deaths.