OBJECTIVETo explore the pathologic features and prognosis of early and late onset severe preeclampsia.

METHODSAn observational study was conducted in 178 cases of severe preeclampsia collected during January 2010 to December 2014 from Haidian Maternal and Child Health Hospital.The cases were divided into two groups according to the onset of gestational age of the severe preeclampsia, with 54 cases of namely early onset (onset ≤ 34 weeks) and 124 cases of late onset (onset >34 weeks). Clinical characteristics of the patients, perinatal outcome and the pathologic characteristics of the placentas in each group were evaluated.

RESULTSDecidual vascular disease, placental infarction, abruptio placentae and placental villi dysplasia were seen in both groups. The incidence of placental villi dysplasia was the highest, followed by placental infarction. Incidence of severe decidual vascular disease of early and late onset severe decidual vascular disease were 16.7% (9/54) and 5.6% (7/124), respectively.Incidence of placental infarction of early and late onset severe preeclampsia were 48.1% (26/54) and 61.3% (76/124). Incidence of placental villi dysplasia of early and late onset severe preeclampsia were 79.6% (43/54) and 50.8% (63/124). Incidence of Severe decidual vascular disease, placental infarction and placental villi dysplasia were significantly different between early and late onset severe preeclampsia cases (P<0.05), while there was no difference in decidual vascular disease and placenta thrombi (P>0.05). Fetal survival rate of every group was 81.5% (44/54) and 93.5% (116/124). Incidence of fetal growth retardation was 55.6% (30/54) and 38.7% (48/124). The fetal survival rate and incidence of fetal growth retardation were different between two groups (P<0.05).

CONCLUSIONSThe incidence of decidual vascular disease and placental villi dysplasia in early onset severe preeclampsia is higher than those in late onset severe preeclampsia. Neonatal outcome and prognosis in early onset severe preeclampsia are worse than those in late onset severe preeclampsia.