Racial Differences in Postpartum Blood Pressure Trajectories Among Women After a Hypertensive Disorder of Pregnancy

Abstract

Importance: Maternal morbidity and mortality are increasing in the United States, most of which occur post partum, with significant racial disparities, particularly associated with hypertensive disorders of pregnancy. Blood pressure trajectory after a hypertensive disorder of pregnancy has not been previously described. Objectives: To describe the blood pressure trajectory in the first 6 weeks post partum after a hypertensive disorder of pregnancy and to evaluate whether blood pressure trajectories differ by self-reported race. Design, Setting, and Participants: This prospective cohort study included deliveries between January 1, 2018, and December 31, 2019. Women with a clinical diagnosis of a hypertensive disorder of pregnancy were enrolled in a postpartum remote blood pressure monitoring program at the time of delivery and were followed up for 6 weeks. Statistical analysis was performed from April 6 to 17, 2020. Main Outcomes and Measures: Mixed-effects regression models were used to display blood pressure trajectories in the first 6 weeks post partum. Results: A total of 1077 women were included (mean [SD] age, 30.2 [5.6] years; 804 of 1017 White [79.1%] and 213 of 1017 Black [20.9%]). Systolic and diastolic blood pressures were found to decrease rapidly in the first 3 weeks post partum, with subsequent stabilization (at 6 days post partum: mean [SD] peak systolic blood pressure, 146 [13] mm Hg; mean [SD] peak diastolic blood pressure, 95 [10] mm Hg; and at 3 weeks post partum: mean [SD] peak systolic blood pressure, 130 [12] mm Hg; mean [SD] peak diastolic blood pressure, 85 [9] mm Hg). A significant difference was seen in blood pressure trajectory by race, with both systolic and diastolic blood pressure decreasing more slowly among Black women compared with White women (mean [SD] peak systolic blood pressure at 1 week post partum: White women, 143 [14] mm Hg vs Black women, 146 [13] mm Hg; P =.01; mean [SD] peak diastolic blood pressure at 1 week post partum: White women, 92 [9] mm Hg vs Black women, 94 [9] mm Hg; P =.02; and mean [SD] peak systolic blood pressure at 3 weeks post partum: White women, 129 [11] mm Hg vs Black women, 136 [15] mm Hg; P