Prediction of recurrence of hypertensive disorders of pregnancy between 34 and 37weeks of gestation: a retrospective cohort study

Objective: To assess the recurrence risk of late-preterm hypertensive disease of pregnancy, and to determine whether potential risk factors are predictive. Design: Retrospective cohort study. Setting: Three secondary and three tertiary care hospitals in the Netherlands. Population: We identified women with a hypertensive disorder in the index pregnancy and delivery at 34-37weeks of gestation, between January 2000 and December 2002. Methods: Data were extracted from medical files and women were approached for additional information on subsequent pregnancies. An adverse outcome was defined as the recurrence of a hypertensive disorder in the next subsequent pregnancy. Main outcome measures: Absolute risk of recurrence and a prediction model containing demographic and clinical factors predictive for adverse outcome. Results: We identified 425 women who matched the criteria, of whom 351 could be contacted. Of these women, 189 (54%) had had a subsequent pregnancy. Hypertensive disorders recurred in 96 (51%, 95% CI 43-58%) women, of whom 17 (9%, 95% CI 5-14%) delivered again before 37weeks of gestation. Chronic hypertension and maternal age were the strongest predictors for recurrence. Women undergoing recurrence had a nine-fold chance of developing chronic hypertension (37% versus 6%, OR8.7, 95%CI 3.3-23). Conclusions: Women with hypertensive disorders and late-preterm delivery have a 50% chance of recurrence, but only a 9% chance of recurrence resulting in delivery before 37weeks of gestation. Women with chronic hypertension are prone to develop recurrence, and women with a recurrence more often developed chronic hypertension. [PUBLICATION ABSTRACT]