Objective: To compare maternal and perinatal outcomes between randomized trials and observational studies in which conservative management was performed for more than 48 h in patients with early-onset severe preeclampsia.
Methodology: We searched PubMed, LILACS, Cochrane and Google Scholar. The studies were divided in two groups: randomized and observational studies, from 1990 to 2018 that included patients with severe preeclampsia before 34 weeks of gestation with pregnancy prolongation ≥48 h but that did not include fetal growth restriction or HELLP syndrome at the beginning. The main variables recorded were maternal and perinatal complications.
Main results: Forty-four studies met the inclusion criteria, and 5 of these were randomized. The average pregnancy prolongation was 9 days, with no difference between groups. Maternal complications were significantly more common in observational studies, RR = 0.71, 95% CI (0.54-0.93), p = .009. Perinatal complications were also significantly more common in observational studies (RR = 0.89, 95% CI (0.80-0.98), p = .01) at the expense of stillbirth and neonatal deaths. The percentages of cesarean sections were significantly higher in randomized studies, RR = 1.54, 95% CI (1.46-1.64). There were 2 maternal deaths, both in observational studies.
Conclusion: Observational studies in which conservative management of early-onset preeclampsia is performed and do not include patients with fetal growth restriction or patients with HELLP syndrome and where at least 2 days of pregnancy prolongation is achieved are associated with significantly more maternal and perinatal complications.
Keywords: HELLP syndrome; Randomized controlled trial; conservative management; early-onset severe preeclampsia; observational trial; severe preeclampsia; stillbirth.