The PRIUM study will include 10 cases of fetuses with prenatal diagnosis of SB and for whom the maternal willing will be to continue the pregnancy. A surgical prenatal repair of the defect will be planed at 19-25+6 weeks gestation following maternal laparotomy and hysterotomy under maternal general anesthesia. The delivery will be planed at 36 weeks'. Postnatal evaluation of the neonates will be scheduled at birth, 1 month and 12 months od age. Those data will be matched to controls who have underwent a conventional postnatal repair of the SB