Blood Pressure Trajectories Through the First Year Postpartum in Overweight or Obese Individuals Following a Hypertensive Disorder of Pregnancy

Background: Hypertensive disorders of pregnancy are associated with cardiovascular disease; however, patterns of blood pressure (BP) recovery are understudied. We compared pregnancy and postpartum BP trajectories among individuals with hypertensive disorders of pregnancy who developed persistent hypertension at 1-year postpartum compared with individuals with normalization of BP. Methods: We used data from a randomized clinical trial of individuals with overweight, obesity, and hypertensive disorders of pregnancy conducted in the first year after delivery. Pregnancy BPs were obtained during prenatal visits; postpartum BPs were prospectively obtained through home monitoring. Demographic characteristics and trajectories were compared by hypertensive status (systolic BP ≥130 mm Hg, diastolic BP ≥80 mm Hg, or use of antihypertensive medications) at 1 year. We used repeated BP measures to fit separate mixed-effects linear regression models for pregnancy and postpartum using restricted cubic splines. Results: We included 129 individuals; 75 (58%) individuals progressed to hypertension by 1-year postpartum. Individuals with hypertension were older, delivered at earlier gestational ages, and had higher body mass index at 1-year postpartum compared with those with normalization. Individuals with hypertension had similar BP trajectories during pregnancy to those with BP normalization but a significantly different BP trajectory ( P <0.01 for systolic and diastolic BPs) in the first year postpartum. These differences persisted in multivariable models after adjustment for early pregnancy body mass index, age, and severity of hypertensive disorder of pregnancy ( P <0.01 for systolic and diastolic BPs). Conclusions: BP trajectories in the first year postpartum, but not during pregnancy, may provide important information for risk stratification after a hypertensive disorder of pregnancy. REGISTRATION: URL: https://clinicaltrials.gov ; Unique identifier: NCT03749746.