Are early and late preeclampsia distinct subclasses of the diseasewhat does the placenta reveal

Objective. To compare histopathological differences in placentas from early- and late-onset preeclampsia, as well as late-onset preeclampsia and normal term deliveries. Methods. This prospective study was performed at Tygerberg Hospital, a secondary and tertiary referral center in South Africa. Placentas from 100 women, 25 each with early and late-onset preeclampsia, and an equal number of controls matched for gestational age, underwent routine preparation and were evaluated independently by two pathologists in a strictly predetermined, standardized manner. Results. Compared to late preeclampsia, placentas in the early preeclampsia group were smaller (p < 0.01), had more infarction (odds ratio [OR] 4.03, 95 confidence interval [CI] 1.213.5) and inappropriate maturation (OR 16.62, 95 CI 4.168.0). Placentas from the late-onset preeclampsia group showed increased decidual arteriopathy (OR 5.09, 95 CI 1.4517.92) and abruptio placentae (OR 5.41, 95 CI 1.0128.79) compared to controls. Conclusions. The early- and late-onset preeclampsia placentas showed clear histopathological differences, whereas late-onset preeclampsia and normal term placentas differed less. These findings support the contention that early- and late-onset preeclampsia are different subclasses of disease. © 2010 Informa Healthcare USA, Inc.