Postpartum management of hypertension and effect on readmission rates

Abstract

Postpartum hypertension is a source of significant morbidity and mortality in the United States. While advances have been made in the peripartum management of hypertension, there is little data to guide ongoing management postpartum. To determine whether an association exists between (1) hospital readmission and (2) hypertension in the 12 hours before discharge and the prescription of antihypertensive medications at the time of discharge. The secondary objective included evaluating the median time to readmission for hypertensive complications. This was a retrospective cohort study of all women with peripartum hypertension at a single tertiary care center over a 3-year period (2017-2019). Peripartum hypertension was defined as any systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg on 2 occasions, 4 hours apart, in the electronic medical record during the patients' admission for delivery. As potential risk factors for readmission, we also identified if the patients were discharged with a prescription for antihypertensive medication and assessed the blood pressure measurements during the 12 hours before discharge. The primary outcome of interest was postpartum readmission because of hypertensive complications. Readmission was defined as emergency room evaluation or hospital readmission because of hypertensive complications. Analysis was stratified into 4 comparison groups on the basis of the blood pressure and antihypertensive medications on discharge. The rate of postpartum readmissions was calculated. The risks of readmission were estimated using logistic regression and were adjusted for appropriate confounding variables. Of 14,577 women who gave birth during the study period, 3480 (24%) met the definition of peripartum hypertension. Of those, 176 (5.1%) were readmitted within a median of 3 days from discharge. Sixty percent of patients readmitted had an International Classification of Diseases, Tenth Revision code for peripartum hypertension assigned by providers during their admission. Women with systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg before discharge were at a higher risk of readmission irrespective of being discharged with antihypertensive medication. Compared with those who were discharged normotensive, women who had hypertension in the 12 hours before discharge and were discharged with an antihypertensive prescription were at a significantly increased risk of readmission, adjusted odds ratio, 2.90; 95% confidence interval, 1.11-7.57. Untreated hypertension within 12 hours before discharge was associated with a 32% higher risk of readmission in those who were not prescribed antihypertensive medications at discharge and a 3-fold increased risk of readmission in patients discharged on antihypertensive medication. These findings highlight the importance of treatment to normalize the blood pressure for at least 12 hours before discharge.