(948) Postpartum health-care utilization and blood pressure control by antihypertensive agent in hypertensive disorders of pregnancy

To evaluate rates of postpartum hospital readmission and emergency room (ER) utilization for individuals with a hypertensive disorder of pregnancy (HDP) after discharge on labetalol versus nifedipine XL.

Study Design: We evaluated outcomes associated with antihypertensive at discharge in a cohort of postpartum individuals delivering from 4/2019-6/2023 at a single institution. Individuals were included who were diagnosed with hypertension (HTN) in pregnancy (including chronic HTN), were discharged on labetalol or nifedipine XL and were enrolled in our institution’s remote blood pressure (BP) management program. Individuals were excluded if they were prescribed antihypertensives antenatally. We compared demographics, inpatient and outpatient BP and clinical outcomes between groups. The primary outcome was postpartum hospital readmission within 8 weeks of delivery. Multivariate logistic regression models adjusted for age, self-identified race, BMI and type of HTN.

Results: 1775 individuals were included; 694 (39.1%) were discharged on labetalol and 1081 (60.9%) on nifedipine XL. Those discharged on labetalol had higher BMIs and higher rates of chronic HTN. Maximum postpartum outpatient systolic BPs were higher in those discharged on labetalol compared to nifedipine (BP 149±15 v 147±13, p=0.03); conversely, maximum diastolic BPs were lower for those on labetalol (BP 96±9 v 98±9, p=0.0002). Compared to individuals discharged on labetalol, those discharged on nifedipine were less likely to have a postpartum hospital readmission (7.3% v 4.3%, p=0.001). In multivariate logistic regression models, discharge on nifedipine was associated with an aOR 0.51 (95%CI 0.31-0.83) decreased odds of postpartum hospital readmission. These findings were similar when stratified by type of HDP (no chronic HTN: aOR 0.54 (95%CI 0.29-0.98); chronic HTN: aOR 0.46 (95%CI 0.20-1.06).

Conclusion: Despite minimal differences in peak postpartum BPs, discharge on nifedipine was associated with less postpartum hospital readmission following a HDP compared to discharge on labetalol, which was robust across type of HDP.