The impact of prior preeclampsia on the risk of superimposed preeclampsia and other adverse pregnancy outcomes in patients with chronic hypertension.

Abstract

We sought to compare the rates of superimposed preeclampsia and adverse outcomes in women with chronic hypertension with or without prior preeclampsia. We conducted secondary analysis of 369 women with chronic hypertension (104 with prior preeclampsia) enrolled at 12-19 weeks as part of a multisite trial of antioxidants to prevent preeclampsia (no reduction was found). Outcome measures were rates of superimposed preeclampsia and other adverse perinatal outcomes. Prepregnancy body mass index, blood pressure, and smoking status at enrollment were similar between groups. The rates of superimposed preeclampsia (17.3% vs 17.7%), abruptio placentae (1.0% vs 3.1%), perinatal death (6.7% vs 8.7%), and small for gestational age (18.4% vs 14.3%) were similar between groups, but preterm delivery <37 weeks was higher in the prior preeclampsia group (36.9% vs 27.1%; adjusted risk ratio, 1.46; 95% confidence interval, 1.05-2.03; P = .032). In women with chronic hypertension, a history of preeclampsia does not increase the rate of superimposed preeclampsia, but is associated with an increased rate of delivery at <37 weeks.