OBJECTIVES: To define and grade fetal and maternal adverse events following fetal surgery for spina bifida and to report on the impact of engaging patients in collecting follow-up data. METHODS: This prospective single-center audit included one hundred consecutive patients undergoing fetal surgery for spina bifida from the first onwards. In our setting, patients return to their referring unit for further pregnancy care and delivery. On discharge, referring hospitals were requested to return outcome data. For this audit, we prompted patients and referring hospitals for missing outcomes. Outcomes were categorized as missing, returned spontaneously or following additional request, and as either provided by the patients or referring center. Postoperative maternal and fetal complications until delivery were defined and graded according to the Maternal and Fetal Adverse Event Terminology (MFAET) and the Clavien-Dindo classification. RESULTS: There were no maternal deaths and seven (7%) severe maternal complications (anemia in pregnancy, postpartum hemorrhage, pulmonary edema, lung atelectasis, urinary tract obstruction, and placental abruption). No uterine ruptures were reported. Perinatal death occurred in 3% and other severe fetal complications in 15% (perioperative fetal bradycardia/cardiac dysfunction, fistula-related oligohydramnios, and preterm rupture of membranes
