OBJECTIVE: HELLP syndrome exposes to severe maternal and fetal complications. Prompt delivery is thus recommended after 34 weeks of gestation, or earlier in case of nonreassuring maternofetal conditions. However, no consensus has been raised in the treatment of HELLP syndrome occurring before 34 weeks of gestation, when both maternal and fetal conditions are stable: it remains still unclear whether an active attitude should be prioritized over expectant management. Herein, we aimed to compare mother and child outcomes according to the type of obstetrical management, either active or conservative. STUDY DESIGN: Retrospective and multicenter study involving two tertiary care units. In Center A, obstetrical attitude consisted in expectant management: all women received full antenatal betamethasone therapy and pregnancy was prolonged until maternal or fetal follow up indicated delivery. In Center B, management was active: all deliveries were initiated within 48 hours following diagnosis. RESULTS: From 2003 to 2011, 118 patients were included (87 in Center A, 31 in Center B). Both groups of patients were similar regarding maternal and fetal features at baseline. Active management led to increased risks of post-partum hemorrhage (relative risks (RR) = 5.38, 95%CI: 1.2-24.06) and neonatal morbidity including respiratory distress syndrome (RR = 3.1, 95%CI: 1.4-7.1), sepsis (RR = 2.5, 95%CI: 1.1-6.0), necrotizing enterocolitis (RR = 4.8, 95%CI: 1.1-21.2), intracerebral hemorrhage (RR = 5.4, 95%CI: 2.1-13.6), and blood transfusion (RR = 6.1, 95%CI: 1.7-21.7). CONCLUSIONS: Conservative management may be beneficial for both mother and newborn in patients with stable HELLP syndrome. Identification of maternal and fetal specific prognostic factors would allow a better stratification of women with HELLP syndrome according to illness progressive potential, resulting in a more personalized management.