Based on this hypothesis, open fetal surgical repair of MMC was proposed, and the recent publication of the NICHD sponsored randomized controlled trial demonstrated clear neonatal benefit of open in-utero fetal surgical repair of MMC. The study showed a reduction in the incidence of hydrocephalus and in the radiographic severity of hindbrain herniation (relative risk: 0.67; 95% confidence interval: 0.56-0.81).