Preeclampsia in the parous woman: Who is at risk?

OBJECTIVE: The purpose of this study was to identify risk factors for preeclampsia in second pregnancies and to determine whether gestational age at delivery in the first pregnancy increases the risk of recurrent preeclampsia. STUDY DESIGN: We conducted a population-based, case-control study using birth certificate data from the Missouri maternally linked cohort. Data from women delivered of their first 2 singleton pregnancies between 1989 and 1997 (2332 cases with preeclampsia in the second pregnancy and 2370 control cases) were analyzed with logistic regression. RESULTS: Significant risk factors for preeclampsia in a second pregnancy include longer birth interval, previous preterm delivery, previous small-for-gestational-age newborn, renal disease, chronic hypertension, diabetes mellitus, obesity, black race, and inadequate prenatal care. Smoking and same paternity are protective. A history of preeclampsia confers the highest risk for preeclampsia in the second pregnancy; the risk is inversely proportional to gestational age at delivery of the first pregnancy: adjusted odds ratio, 15.0; 95% Cl, 6.3-35.4 for 20 to 33 weeks; adjusted odds ratio, 10.2; 95% Cl, 6.2-17.0 for 33 to 36 weeks; and adjusted odds ratio, 7.9; 95% Cl, 6.3-10.0 for 37 to 45 weeks. CONCLUSION: The relative risk of recurrent preeclampsia increases with earlier gestational age at delivery of the first pregnancy that was complicated by preeclampsia.