Abstract Body: Introduction Postpartum hypertension is a leading cause of severe maternal morbidity, yet most patients receive a single blood pressure (BP) check before the 6-week visit. Remote BP monitoring (RBPM) programs address this gap by enabling continuous postpartum surveillance. At a large safety-net hospital, patients with hypertensive disorders of pregnancy (HDP) were provided RBPM cuffs as part of routine postpartum care, allowing for daily BP tracking. This cohort study estimated time to hypertension resolution during the first 6 weeks (42 days) postpartum among RBPM patients, overall and by HDP subtype.

Hypothesis Time to hypertension resolution is expected to be longest among patients with preeclampsia, often the most severe HDP subtype, compared to those with gestational or de novo postpartum hypertension.

Methods This cohort study included patients who delivered between January 2021 and June 2023 and recorded ≥2 daily BP measurements using a RBPM cuff after an HDP diagnosis. HDP subtypes included gestational hypertension, preeclampsia, and de novo postpartum hypertension detected during the delivery hospitalization; patients with chronic hypertension were excluded. Hypertension resolution was defined as ≥2 consecutive days of normal BP (systolic BP <130 and diastolic BP <80 mmHg) without antihypertensive medication use. A lenient definition (≥1 vs ≥2 days of normal BP) was also examined. Time to resolution through 42 days postpartum was estimated using Kaplan-Meier methods, overall and by HDP subtype; patients not achieving resolution were censored after ≥7 consecutive days without BP measures or at day 42.

Results Among 1,773 patients, 31.5% met the definition of hypertension resolution over the 6-week postpartum period. Those who achieved resolution were less likely to be English speakers (47.7% vs 58.3%), born in the United States (28.5% vs 38.0%), and have a preterm birth (9.5% vs 18.5%) compared with those censored. Average time to resolution was 15.0 days (SD 10.1). By HDP subtype, average time to resolution was 13.2 days (SD 8.7) for gestational, 13.6 days (SD 8.7) for de novo postpartum, and 19.0 days (SD 12.0) for preeclampsia. Under the lenient definition, 62.6% met hypertension resolution at 10.0 days on average (SD 10.5).

Conclusions On average, patients required >2 weeks to reach hypertension resolution. Less stringent definitions of resolution may misclassify patients as normotensive, emphasizing the need for longer-term BP monitoring.