Fetal Myelomeningocele Repair Homepage

Authors

Michael C. Dewan, MD, MSCI
John C. “Jay” Wellons, MD, MSPH

Section Editors

Bermans Iskandar, MD
Graham Fieggen, MD

Editor in Chief

Rick Abbott, MD

Introduction

The two-hit neural injury hypothesis, which consists of spinal cord damage from failed neurulation (first hit), followed by additional injury presumably due to exposure of the cord to amniotic fluid (second hit), presents an opportunity to preserve function and reverse early neurologic deterioration in the fetus via prenatal repair. Indeed, patients treated prenatally in the MOMS trial showed a reduced need for CSF shunting and improved neurologic function (1). Additional clinical investigations have offered insight into urologic, orthopedic, radiologic, and maternal factors that may impact fetal repair. Long-term neurocognitive and motor function data are limited but are on the horizon. Technological developments such as fetoscopic surgery may minimize patient morbidity while maintaining the established benefits seen with open intrauterine repair.

Key Points

• Two-hit hypothesis: After the neurologic insult of failure of primary neurulation, exposure of the neural elements during gestation causes further neurologic deterioration (9). Prenatal intervention may salvage neurologic function.
• MOMS trial: This randomized study of fetal versus postnatal repair of myelomeningocele demonstrated a reduced need for shunting and improved early neurologic function following intrauterine repair (1).
• Obstetric and maternal considerations: Fetal repair is associated with premature birth, chorionic membrane separation, and premature rupture of membranes (3). Subsequent pregnancies require caesarean delivery.
• Neurocognitive outcomes: Preliminary data suggest similar long-term neurocognitive outcomes between pre- and postnatally treated patients but improved physical outcomes in prenatally treated patients (5).