A Randomized Trial of Prenatal versus Postnatal Repair of Myelomeningocele [Widely known as the Management of Myelomeningocele (MOMS) Trial]

This was a randomized trial of prenatal repair of myelomeningocele (the most common form of spina bifida) with the standard postnatal repair with the hypothesis that there would be improved neurologic function. Methods: Eligible women recruited from three American fetal medicine centers either underwent prenatal surgery before 26 weeks of gestation or standard postnatal repair. There were two primary outcomes: a composite of fetal or neonatal death or the need for placement of a cerebrospinal fluid shunt by the age of 12 months and a composite of mental development and motor function at 30 months. Results: The trial was stopped for efficacy of prenatal surgery after the recruitment of 183 of a planned 200 patients. The report is based on results in 158 patients whose children were evaluated at 12 months. The first primary outcome occurred in 68% of the infants in the prenatal-surgery group and in 98% of those in the postnatal-surgery group (relative risk, 0.70; 97.7% confidence interval [CI], 0.58 to 0.84; P < 0.001). Actual rates of shunt placement were 40% in the prenatal-surgery group and 82% in the postnatal-surgery group (relative risk, 0.48; 97.7% CI, 0.36 to 0.64; P < 0.001). Prenatal surgery also resulted in improvement in the composite score for mental development and motor function at 30 months (P = 0.007) and in improvement in several secondary outcomes, including hindbrain herniation by 12 months and ambulation by 30 months. However, prenatal surgery was associated with an increased risk of preterm delivery and uterine dehiscence at delivery.Conclusions: Prenatal surgery for myelomeningocele reduced the need for shunting and improved motor outcomes at 30 months but was associated with maternal and fetal risks.