[Study on different onset patterns and perinatal outcomes in severe preeclampsia].

Objective: To explore the different clinical onset patterns in severe preeclampsia.

Methods: A prospective observational study was conducted in 173 cases of severe preeclampsia. They were divided into two groups according to the onset of gestational age of severe preeclampsia, early onset of severe preeclampsia (S-PE) (onset < or = 34 weeks) and late onset of S-PE (onset > 34 weeks). Then according to the onset pattern they were subdivided into 4 subgroups: early abrupt onset (10) and early onset with gradual progress of severe preeclampsia (87), late abrupt onset (18) and late onset with gradual progress of severe preeclampsia (58). Clinical characteristics in each subgroup were evaluated.

Results: Cases with abrupt onset accounted for 16.2% out of 173 cases of severe preeclampsia (28/173). The incidence of abrupt onset or onset with gradual progress between early and late onset groups was not significantly different (P > 0.05). Whether in early onset group or late onset group, the incidence of serious maternal complications was much higher in abrupt onset subgroups than that in gradual progress subgroups [100.0% (10/10) vs 34.5% (30/87) and 100.0% (18/18) vs 29.3% (17/58); P < 0.001]. The incidence of serious maternal complications was not significantly different between early onset and late onset groups (P > 0.05). The perinatal mortality rate was higher in abrupt onset subgroups compared to gradual progress subgroups both in early onset groups and in late onset ones (72.7% vs 24.3%, P < 0.01; 22.2% vs 4.9%, P < 0.05). The perinatal mortality rate was higher in each subgroups in early onset groups than that in late onset ones respectively (P < 0.01, P < 0.05). The gestational age at delivery was closely associated with perinatal outcomes. When a delimitation of early onset of severe preeclampsia was set at 32-week gestation, perinatal outcome was associated with both gestational age at birth and the onset time of severe preeclampsia. If the cut-off point was set at 34-week gestation, perinatal outcome was associated only with gestational age at birth.

Conclusions: Approximately 16% pregnant women with severe preeclampsia were attacked abruptly and complicated by serious complications. The clinical delimitation of early onset of severe preeclampsia set at 32-week gestation is significantly associated with poor maternal and perinatal outcomes.