Investigation of factors that predict risk for hospital readmission following delivery of pregnancies complicated by hypertensive disorders of pregnancy

Objective: The aim of this study was to evaluate specific risk factors and their impact on hospital readmission risk following delivery in pregnancies affected by the hypertensive disease of pregnancy (HDP). Methods: We performed a 10-year case-control study for patients who delivered at our institution and whose antenatal courses were complicated by HDP. The primary outcome was the identification of specific patient factors contributing to readmission. HDP pregnancies experiencing readmission for HDP signs and/or symptoms were used as the cases, with HDP pregnancies not experiencing readmission randomly selected as controls. Maternal age, gestational age at delivery, gravidity, parity, and mode of delivery (vaginal including operative, or cesarean) were recorded. Mean systolic and diastolic blood pressures were calculated over the 24 h preceding discharge. The most recent laboratory values preceding discharge for serum creatinine, lactate dehydrogenase, aspartate aminotransferase, alanine transaminase, and platelets were also recorded. The presence or absence of prescribed antihypertensive medication was recorded for initial hospitalization. Postpartum readmission was defined as within 30 days of delivery. Exclusion criteria involved readmission for non-HDP cause and maternal age less than 17 at delivery. Results: Within the study timeframe, 3601 patients with pregnancies complicated with HDP were identified. Of these, 34 patients were readmitted within 30 days postpartum for signs and/or symptoms of HDP after exclusion criteria were applied A cohort of 50 controls were used for comparison for a total of 84 participants. A diagnosis of pre-eclampsia was significantly associated with readmission (p=.004) when compared to other HDP diagnoses. Demonstration of severe disease features also was associated significantly (p < 0.001) with readmission. Parity greater than or equal to three also was associated with readmission (p = 0.019). Notably, age, BMI, delivery mode, blood pressure preceding discharge, length of hospital stay, and being discharged with antihypertensive medication were not significantly associated with readmission. Conclusion: This study suggests that readmission overall for the hypertensive disease of pregnancy is rare, but that patient variables of increasing parity and presence of severe features were associated with postpartum readmission. Knowledge of these variables may assist physicians in the identification of HDP patients who are at higher risk for readmission.