Tocolysis for open prenatal repair of myelomeningocele: systematic review

Objectives: To summarize current evidence on the use of tocolytic medications perioperatively for open prenatal repair of fetal myelomeningocele including tocolytic agent options, regimens, efficiency, and potential risks. Methods: A search of Medline, Embase, and SCOPUS databases was conducted from inception to March 2017. Studies that described their tocolytic protocol, gestational age at delivery, perinatal outcomes were included. Studies that did not exclusively assessed fetal myelomeningocele or did not adequately endorse obstetric and neonatal outcomes were excluded. Neither sample size nor language was a basis for exclusion. Results: Out of 570 studies retrieved on initial search, 462 were excluded for irrelevance. Of the 61 remaining titles, 17 were animal studies, 17 were reviews, 12 studied a spectrum of anomalies, three specified fetoscopy, four did not report neonatal outcomes, and one article was retracted. Two studies were added to the pool when the literature search was updated. Nine articles were eventually included; three case reports, six cohort studies with a total of 205 cases. Fetuses were managed at gestational ages between 19 and 30 weeks. Although tocolytic regimens were variable, indomethacin was commonly utilized as a preoperative tocolytic. Magnesium sulfate was usually initiated intraoperatively and was resumed postoperatively for a variable duration (18-48 hours) with or without subcutaneous terbutaline. Gestational age at delivery ranged from 30-37 weeks with an average of 33-35 weeks. Pulmonary edema was reported in two studies to be 2.2-5.5%. Perinatal outcomes were overall favorable. Conclusion: Preoperative indomethacin and postoperative course of magnesium sulfate seem to be a favorable tocolytic option in women with open prenatal myelomeningocele repair. Risks are generally minimal. However, adequate information on the duration of postoperative tocolysis seems to be inadequate.