515: Antepartum hospitalizations for hypertensive diseases of pregnancy and risk for subsequent postpartum readmission

Whether antepartum (AP) inpatient admissions for hypertensive diseases of pregnancy (HDP) are associated with increased risk for postpartum (PP) readmissions is not well characterized. The purpose of this study was to determine whether AP HDP admission is associated with 30-day PP HDP readmission rates. Delivery hospitalizations October and November of 2010 to 2014 were identified using the Nationwide Readmissions Database, a nationally representative discharge database. We identified AP admissions with the primary diagnosis of HDP occurring within 9 months preceding delivery and PP readmissions within 30 days of discharge from delivery. The primary outcome was 30-day HDP readmission. Risk for severe maternal morbidity (SMM) was also analyzed based on CDC criteria. AP admission length of stay of (aLOS) and number of antepartum admissions were also analyzed as risk factors for readmission. Adjusted log linear regression models were used to analyze risk for readmission and morbidity with risk ratios (RR) and 95% confidence intervals (CI) as the measures of effect. 3.1 million deliveries were analyzed with 11,393 (0.4%) antepartum admissions and 8,964 (0.3%) postpartum readmissions. Of the women admitted AP, 92% were admitted only once with median aLOS 1.6 days. AP admission was associated with higher risks of 30-day PP HDP readmission (2.4% vs. 0.3%, p<0.01). In adjusted analysis controlling for the presence of HDP at delivery, patients with an antepartum HDP admission were at 65% higher risk of 30-day postpartum readmission (RR 1.65, 95% CI 1.45, 1.87) (Table 1). Risk for SMM was not significantly increased. Patients who had more than one AP admission further increased risk for readmission. In comparison, aLOS > 7d was significantly associate with a 50% decreased risk for PP HDP readmission (RR=0.50, 95% CI: 0.27, 0.92, p<0.01) (Table 2). AP HDP admission is a risk factor for readmission independent of HDP status at delivery. However, AP admission was not associated with SMM at readmission and increased aLOS was associated with decreased readmission risk. Longer surveillance of patients in the hospital may result in more detailed management plans that subsequently facilitate outpatient management. For patients with AP admissions close interval follow up after delivery discharge may be indicated.View Large Image Figure ViewerDownload Hi-res image Download (PPT)