529: Continuous versus interrupted magnesium for preeclampsia with severe features and blood loss during cesarean delivery

Abstract

Magnesium sulfate is the standard of care for the prevention of eclampsia in women with preeclampsia with severe features. ACOG endorses its use throughout labor, delivery and the immediate postpartum period, even during cesarean delivery (CD). Some providers pause magnesium sulfate infusion during CD due to concern for increased risk of operative blood loss and postpartum hemorrhage. We sought to assess the effect of continuous versus interrupted infusion of magnesium sulfate on operative blood loss and postpartum hemorrhage for women with preeclampsia with severe features. Retrospective cohort study of women undergoing CD with singleton pregnancies and preeclampsia with severe features treated with magnesium sulfate infusion at a tertiary care hospital from 2013-2018. The primary outcome was a composite of postpartum hemorrhage (EBL > 1000mL), transfusion of blood products, use of other uterotonics, or additional surgical interventions. These outcomes were compared between women who received continuous versus interrupted magnesium sulfate infusion during CD. Multivariable analysis controlled for factors found to be statistically significant from baseline and delivery characteristics. Of 249 women, magnesium sulfate infusion was continuous in 78 (31%) and interrupted in 171 (69%) during CD. Women with continuous magnesium sulfate infusion were more likely to be African American (22% vs 13%, p = 0.02), experience prolonged surgical time (55 vs 50 min, p= < 0.01), have a prior cesarean delivery (28% vs 11%, p = < 0.01), and use anticoagulants prior to delivery (19% vs 6%, p < 0.01) (Table 1). There was no difference in the primary outcome (17% vs 14%, p= 0.78). Additionally, there were no significant differences for postpartum hemorrhage (10% vs 10%, p = 0.49), need for transfusion (5% vs 1%, p=0.42) or use of other uterotonics (6% vs 4%, p=0.49) (Table 2). Continuing intraoperative magnesium sulfate infusion for eclampsia prevention does not appear to be an independent risk factor for increased operative blood loss or postpartum hemorrhage.View Large Image Figure ViewerDownload Hi-res image Download (PPT)