Blood pressure changes in gestational hypertension, preeclampsia, and chronic hypertension from preconception to 42-day postpartum

To investigate blood pressure changes from preconception to 42-day postpartum in patients with gestational hypertension, preeclampsia, and chronic hypertension.Secondary analysis of patients diagnosed with a hypertensive disorder of pregnancy (HDP) antenatally or postpartum, who were enrolled prospectively in a postpartum remote blood pressure (BP) monitoring program between March 2017 and May 2020. BP were collected at 47 time points: preconception, each trimester, delivery day, and every postpartum day through 42-days postpartum. The primary outcome of the study was to examine changes in BP over time and between the types of HDP for 42 days postpartum. Secondary outcomes included the difference in timing of BP stabilization (BPs < 140/90 mmHg for ≥ 48 h), BP resolution (stabilized without antihypertensive medication use), and antihypertensive medication usage at 42-day postpartum between the HDP groups.A total of 1,194 patients were included in the cohort; 224 (18.8 %) had chronic hypertension (CHTN), 525 (43.9 %) had gestational hypertension (GHTN), 153 (12.8 %) had preeclampsia, and 292 (24.5 %) had preeclampsia with severe features. Postpartum BP peaked on days 5-7 postpartum with rapid decrease from postpartum day 7 until postpartum day 14, followed by very small resolution/stabilization in BP values between day 15 and 42 postpartum. By 6 weeks postpartum, 60.5 % of patients with CHTN still required antihypertensive medications to maintain BP < 140/90 mmHg. In the group of patients with preeclampsia with severe features, 32.6 % still required antihypertensive medications to maintain BP < 140/90 mmHg. Finally, 16.1 % patients with GHTN and 23.8 % of patients with preeclampsia without severe features required antihypertensive use at 6 weeks postpartum. The groups of CHTN and GHTN had significant reduction in SBPs at 42-days postpartum compared to their pre-conception BP (p < 0.001 for both groups). While diastolic BP at 42-days postpartum were not different in CHTN, GHTN and preeclampsia groups, compared to preconception, women with preeclampsia with severe features had higher diastolic BP at the end of 6-weeks postpartum period compared to preconception readings (p = 0.007).Our study adds new information by examining BP trajectories through 42 days postpartum and demonstrates that all types of HDP are at risk of BP spikes and intervention through 42 days postpartum. We found that patients with CHTN had slower stabilization and resolution of their BP compared to patients with GHTN and preeclampsia with and without severe features. In addition, even at 42 days postpartum, a substantial proportion of patients with HDP, including GHTN, required antihypertensive treatment to maintain BP within stage I hypertension.