Magnesium sulfate titration reduces maternal complications following fetoscopic closure of spina bifida.

OBJECTIVE To evaluate if magnesium sulfate (MgSO4 ) titration following fetoscopic spina bifida closure is associated with fewer maternal complications than the Management of Myelomeningocele Study (MOMS) tocolytic regimen. METHODS This prospective cohort study included 73 consecutive patients undergoing fetoscopic closure of spina bifida between 2015 and 2020. A policy of using the MgSO4 regimen per the MOMS trial was changed to a flexible one in which MgSO4 was titrated according to the frequency of the uterine contractions following surgery. The frequency of maternal pulmonary edema, low maternal oxygen saturation requiring oxygen supplementation, atelectasis, hypocalcemia, and preterm delivery was compared before and after the policy was changed. RESULTS A higher proportion of women in the group that used the MOMS MgSO4 regimen had pulmonary edema compared to those in the flexible one (26.1% [6/23] vs. 6% [3/50]; p = 0.024). Multivariate analysis showed that the MOMS tocolytic regimen was independently associated with a higher risk of pulmonary edema (adjusted odds ratio: 8.57; 95% confidence interval: 1.54-47.7; p = 0.014) than a flexible one. There was no difference in the rate of preterm delivery. CONCLUSION Following fetoscopic closure of spina bifida, the MOMS MgSO4 regimen is associated with an increased risk of pulmonary edema than a more flexible regimen.