Blood Pressure During Hospital Stay for Delivery and Risk for Postpartum Readmission for Hypertension

Abstract

OBJECTIVE: To evaluate the association of changes in peripartum blood pressure (BP) with risk for postpartum readmission for hypertension. METHODS: We conducted a retrospective cohort study of birthing individuals delivering from January 1, 2017, to March 1, 2020, in Louisiana. We identified patients with postpartum readmission for hypertension (readmission within 30 days of delivery) and compared BP and clinical and sociodemographic characteristics with those of patients who were not readmitted for hypertension. Patients were also grouped by their BP at both admission for delivery and 36 hours postpartum: systolic below 130 mm Hg and diastolic below 80 mm Hg, systolic 130–139 mm Hg or diastolic 80–89 mm Hg, systolic 140–149 mm Hg or diastolic 90–99 mm Hg, and systolic 150 mm Hg or higher or diastolic 100 mm Hg or higher. Logistic regression was performed to identify risk factors for postpartum readmission for hypertension. RESULTS: In our cohort of 17,587 individuals, 329 patients (1.9%) experienced postpartum readmission for hypertension. Increased admission BP (adjusted odds ratio [aOR] 2.26, 95% CI, 1.75–2.928), increased 36-hour postpartum BP (aOR 2.36, 95% CI, 1.58–3.53), and preeclampsia (aOR 2.47, 95% CI, 1.83–3.34) were the strongest predictors of postpartum readmission for hypertension. Black race, anemia, and increased maternal age also significantly increased the odds of postpartum readmission for hypertension (all P<.001). Elevated BP on admission for delivery showed a stepwise increased incidence of postpartum readmission for hypertension (percent readmitted among the four admission BP groups: 6.0%, 2.8%, 1.6%, and 0.7% in the 150/100 mm Hg or higher group [highest], 140–149/90–99 mm Hg group, 130–139/80–89 mm Hg group, and less than 130/80 mm Hg group [lowest], respectively). CONCLUSION: Even mildly elevated BP at delivery admission and persisting postpartum significantly increased risk for postpartum readmission for hypertension.