Perinatal outcomes in women with preeclampsia and superimposed preeclampsia: do they differ?

ObjectiveThe purpose of this study was to determine whether superimposed preeclampsia results in worse perinatal outcomes than preeclampsia.Study DesignWe conducted a retrospective cohort study using our perinatal database (1990-2008). Perinatal outcomes among women with chronic hypertension (n = 1032), superimposed preeclampsia (n = 489), and preeclampsia (n = 4217) were compared with outcomes of control subjects (n = 57,103). Outcomes among women with superimposed preeclampsia were also compared with outcomes of women with preeclampsia. Multivariable analysis was used to control for confounders.ResultsRates of small-for-gestational age, abruption, stillbirth, and eclampsia were not significantly different with superimposed preeclampsia compared with preeclampsia. Delivery at <34 weeks' gestation (17.3% vs 8.7%; P < .001), cesarean delivery (46.2% vs 36.3%; P < .001), and neonatal intensive care unit admission (16.3% vs 11.4%; P < .002) were significantly higher among women with superimposed preeclampsia. These risks persisted after we controlled for confounders.ConclusionWomen with superimposed preeclampsia have higher risks of intervention-related events compared with those with preeclampsia.