508: Readmission Following Discharge on Labetalol or Nifedipine for Management of Hypertensive Disorders of Pregnancy

Hypertensive disorders of pregnancy (HDP) confer significant maternal risks postpartum including risks of seizure, stroke and higher rates of postpartum readmission. Following delivery, women with blood pressure elevations are treated primarily with labetalol or nifedipine but it is unknown if one agent is more effective for blood pressure control following hospital discharge. We sought to compare rates of postpartum readmission and adverse maternal outcomes based on discharge on labetalol versus nifedipine. We identified women 15 to 44 years of age with a delivery admission in the Truven Health MarketScan® Commercial Claims and Encounters Database (2011-14) who were discharged on labetalol or nifedipine based on having a prescription filled either during the delivery admission or within 4 days of discharge. Two groups of HDP were examined: 1) gestational hypertension/preeclampsia without severe features and 2) preeclampsia with severe features/eclampsia. We calculated the rates of readmission for eclampsia, stroke or any reason up to 6 weeks postpartum by medication and indication for use and the odds of readmission for each medication within HDP groups. Among our cohort of 980,666 deliveries, 6.4% experienced gestational hypertension/preeclampsia without severe features (mild disease) and 2.5% severe preeclampsia/eclampsia. 28.5% of women with mild disease and 39.3% with severe preeclampsia/eclampsia were discharged on either medication. The overall readmission rate in the cohort was 1.1% (n=11,016). Rates of readmission increased with increasing severity of HDP: mild disease 2.2% (p<0.001), and severe preeclampsia/eclampsia 3.3% (p<0.001). Across all HDP groups, readmission rates tended to be higher for women discharged on labetalol (4.3%-5.2%) (Table). Specifically, when compared to women discharged without medications, women with mild disease discharged on labetalol were more likely to be readmitted with eclampsia (OR 4.39, 95% CI 3.24-5.94) and women with severe preeclampsia were more likely to be readmitted for any reason (OR 1.51, 95% CI 1.29-1.77). Women with HDP represent a high-risk group for postpartum readmission. Compared to nifedipine, discharge on labetalol is associated with increased rates of readmission for severe manifestations of HDP, eclampsia and stroke.