Magnesium sulphate can prolong pregnancy in patients with severe early-onset preeclampsia

<i>Objective</i>: To assess whether long-term use of magnesium sulphate prolongs pregnancy in patients with severe early-onset preeclampsia. <i>Methods</i>: Retrospective cohort study included all singleton pregnancies with severe early-onset preeclampsia, expectantly managed in our institution between 2005 and 2013. Obstetric and perinatal outcomes were compared between patients managed using a current protocol that tolerates long-term (over 48 h) use of magnesium sulphate (long-term group, <i>n</i> = 26) and a historical control group (control group, <i>n</i> = 15) that underwent conventional treatment (up to 48 h use of magnesium sulphate). <i>Results</i>: Long-term group showed significant prolongation of pregnancy compared with the control group (9.2 ± 7.9 versus 16.6 ± 9.3 d, log-rank test, <i>p</i> = 0.021), which was also observed in patients with severe preeclampsia occurring before 28 weeks’ gestation (<i>n</i> = 11, 4.5 ± 5.2 versus 13.2 ± 6.8 d, log-rank test, <i>p</i> = 0.035). In contrast to a progressive decrease of platelet count in patients managed without magnesium sulphate, administration of magnesium sulphate for 7 d prevented the decrease of platelet count (<i>p</i> = 0.001). Thirty two percent of patients (13/41) experienced a major complication irrespective of duration of magnesium sulphate use. <i>Conclusions</i>: Long-term use of magnesium sulphate prolonged pregnancy in patients with severe early-onset preeclampsia and can help alleviate progression of preeclampsia.