Does magnesium sulfate increase the incidence of postpartum hemorrhage? A systematic review

Laura M. Héman, Paul J. Q. Van Der Linden

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DOI: 10.4236/ojog.2011.14032                

Abstract

The incidence of Postpartum Hemorrhage (PPH) is increasing in the western world. We hypothesize that magnesium sulfate (MgSO₄) could be a contributing factor. MgSO₄ might increase the incidence of PPH by induction of vasodilation, tocolytic effects, and effects on the blood like red cell deformity, platelet activity inhibition and a prolonged bleeding time. Based on these effects of MgSO₄ a correlation with PPH is suspected. MgSO₄ is widely used in the prevention of eclampsia. However, the working mechanism of this effective drug is largely unknown. We performed a systematic search to find all Randomized Controlled trials (RCTs) containing MgSO₄ in preeclamsia as well as all MgSO₄ studies with information on PPH. Titles, abstracts and references of publications were evaluated for appropriateness and whether they met the inclusion criteria. RCTs about MgSO₄ with original data on PPH prevalence were included in our systematic review. We calculated the relative risk of PPH in every study as well as an overall relative risk. Four relevant and valid RCTs were found, totalling 11,621 relevant patients. The relative risk of PPH in women treated with MgSO₄ is 0.964 (95% CI 0.886 - 1.050) In this systematic review we found no significant increase in PPH in women treated with MgSO₄. However, there is still room for discussion due to the heterogeneity in methods (dosage and duration of treatment), results, and tertiary outcomes, as well as the small number of studies found with respect to this important issue.

Keywords

Magnesium Sulfate (MgSO₄); Postpartum Hemorrhage (PPH)

Conflicts of Interest

The authors declare no conflicts of interest.

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