47 Quantifying recurrence risk of preeclampsia in a population-based cohort: Effects of first pregnancy maximum diastolic pressure

Abstract

Introduction Preeclampsia (PE) is a major source of maternal and fetal morbidity that affects 2.5–3.0% of all pregnancies. Recurrence estimates range from 0% to 67%. Such a wide range imposes a difficult challenge in counseling future pregnancies, and so a better assessment of pertinent risk factors for recurrence in the individual patient is required. Objective We aim to estimate the recurrence risk of preeclampsia (PE) in the 2nd pregnancy and investigate the influence of first pregnancy maximum diastolic pressure and additional risk factors. Methods We studied a linked cohort of 1st and 2nd pregnancies of 272.551 women from the Dutch Perinatal Registry collected between 2000 and 2007. We defined PE as hypertension (diastolic blood pressure >90 mmHg) plus proteinuria (>300 mg/24 h), included recorded PE cases and analysed the PE recurrence rate using logistic regression. To avoid potential listwise deletion bias, multiple imputation of missing maximum diastolic blood pressure data was used. Gestational and maternal ages, multiple pregnancy, chronic hypertension, diabetes, ethnicity and socioeconomic status were considered as covariates. Results The overall PE prevalences in the 1st and 2nd pregnancies were 2.4% and 0.9%, respectively. In the 2nd pregnancy the prevalence of PE was 10.4% for women with prior preeclampsia. Early onset PE in the 1st pregnancy with delivery before the 34th week was associated with increased recurrence risk proportional to the maximum diastolic blood pressure (DBP) in the 1st pregnancy: for DBP between 90 and 100 mmHg the recurrence risk was 15% (95% CI 11.1–20.6%) while for DBP above 110 mmHg the risk was 26.6% (95% CI 21.6–32.3%). For women with increased maximum DBP but no history of preeclampsia the corresponding rates were 2.2% (95% CI 2.0–2.4%) and 6.3% (95% CI 5.3–7.5%). Conclusion The overall chance of recurrence of preeclampsia is 10.4%. Early onset preeclampsia complicated by severe hypertension increases this rate to about one in four. Severe hypertension in the 1st pregnancy in women that did not present preeclampsia is a major risk factor for preeclampsia in the following pregnancy. This knowledge can improve patient and physician awareness of the individual risks of occurrence and recurrence of preeclampsia which are fundamental for the proper management of subsequent pregnancies.