Clinical Characteristic and Maternal-Perinatal Outcome of Early-Onset vs Late-Onset Preeclampsia: A Systematic Review

Introduction: Preeclampsia is not a single disease entity. Based on pathophysiological trajectories, Early-Onset Preeclampsia (EO-PE, <34 weeks) is highly associated with primary defective placentation and failed spiral artery remodeling, whereas Late-Onset Preeclampsia (LO-PE, ≥34 weeks) correlates more with maternal cardiometabolic decompensation. This review aims to evaluate the clinical significance of these pathophysiological differences on pregnancy outcomes. Method: This systematic review evaluated 12 primary observational studies. The primary focus of the review was to compare the severity of maternal and perinatal outcomes between patient groups with EO-PE and LO-PE. Results and Discussion: The literature synthesis demonstrated substantial differences in clinical profiles. EO-PE patients had a significantly lower gestational age at termination and lower mean birth weight due to the urgency of iatrogenic delivery. The EO-PE group consistently dominated the incidence of severe systemic maternal complications, including HELLP syndrome and placental abruption. Regarding perinatal outcomes, infants of EO-PE mothers bore massive morbidities, including increased risks of extreme prematurity, fetal growth restriction, low Apgar scores, and a high need for Perinatal Intensive Care Unit (NICU) admission. Conversely, although lethal complications were generally lower in LO-PE, the literature revealed a paradoxical outcome where the incidence of Postpartum Hemorrhage (PPH) was reported to be higher in this late-onset group. Conclusion: EO-PE consistently presents a substantially more lethal spectrum of maternal and perinatal complications compared to LO-PE. This worsening clinical profile underscores the urgency of implementing early detection strategies, specific risk stratification based on the time of onset, and proactive mobilization of advanced NICU facilities in cases of early-onset preeclampsia.