Postpartum Ambulatory Blood Pressure Patterns Following New-Onset Hypertensive Disorders of Pregnancy

Abstract

Importance

After a hypertensive disorder of pregnancy, hypertension can worsen in the postpartum period following hospital discharge. Risk factors for ongoing hypertension and associated outcomes have not been well characterized.

Objective

To identify risk factors and characterize outcomes for individuals with ongoing hypertension and severe hypertension following hospital discharge post partum through a hospital system’s remote blood pressure (BP) management program.

Design, Setting, and Participants

This cohort study involved a population-based sample of individuals with a new-onset hypertensive disorder of pregnancy (preeclampsia or gestational hypertension) and no prepregnancy hypertension who delivered between September 2019 and June 2021. Participants were enrolled in a remote BP monitoring and management program at a postpartum unit at a referral hospital. Data analysis was performed from August 2021 to January 2023.

Exposure

Inpatient postpartum BP categories.

Main Outcomes and Measures

The primary outcomes were readmission and emergency department visits within the first 6 weeks post partum. Logistic regression was used to model adjusted odds ratios (aORs) and 95% CIs.

Results

Of 2705 individuals in the cohort (mean [SD] age, 29.8 [5.7] years), 2214 (81.8%) had persistent hypertension post partum after hospital discharge, 382 (14.1%) developed severe hypertension after discharge, and 610 (22.6%) had antihypertensive medication initiated after discharge. Individuals with severe hypertension had increased odds of postpartum emergency department visits (aOR, 1.85; 95% CI, 1.17-2.92) and hospital readmissions (aOR, 6.75; 95% CI, 3.43-13.29) compared with individuals with BP normalization. When inpatient postpartum BP categories were compared with outpatient home BP trajectories to inform optimal thresholds for inpatient antihypertensive medication initiation, there was significant overlap between postdischarge BP trajectories among those with inpatient systolic BP greater than or equal to 140 to 149 mm Hg and/or diastolic BP greater than or equal to 90 to 99 mm Hg and those with systolic BP greater than or equal to 150 mm Hg and/or diastolic BP greater than or equal to 100 mm Hg.

Conclusions and Relevance

This cohort study found that more than 80% of individuals with hypertensive disorders of pregnancy had ongoing hypertension after hospital discharge, with approximately 14% developing severe hypertension. These data support the critical role of remote BP monitoring programs and highlight the need for improved tools for risk stratification and consideration of liberalization of thresholds for medication initiation post partum.