Open Fetal Surgical Outcomes for Myelomeningocele Closure Stratified by Maternal Body Mass Index in a Large Single-Center Cohort.

BACKGROUND: Open maternal-fetal surgery for in utero closure of myelomeningocele (MMC) has become an accepted treatment option for prenatally diagnosed open neural tube defects. Historically, this option has been limited to women with BMI < 35 due to concern for increasing complications in patients with obesity. OBJECTIVE: The aim of this study was to evaluate maternal, obstetric, and fetal/neonatal outcomes stratified by maternal BMI classification in women who undergo open maternal-fetal surgery for fetal myelomeningocele (fMMC) closure. METHODS: A single-center fMMC closure registry was queried for maternal demographics, preoperative factors, fetal surgery outcomes, delivery outcomes, and neonatal outcomes. Data were stratified based on maternal BMI: <30, 30-34.99, and ≥35-40, corresponding to normal weight/overweight, obesity class I, and obesity class II. Statistical analysis was performed using statistical software SAS v.9.4 (SAS Institute Inc., Cary, NC, USA). RESULTS: A total of 264 patients were analyzed, including 196 (74.2%) with BMI <30, 54 (20.5%) with BMI 30-34.99, and 14 (5.3%) with BMI ≥ 35-40. Maternal demographics and preoperative characteristics were similar among the groups. Operative time increased with increasing BMI; otherwise, perioperative outcomes were similar among the groups. Obstetric and neonatal outcomes were similar among the groups. CONCLUSION: Increasing maternal BMI did not result in a negative impact on maternal, obstetric, and fetal/neonatal outcomes in a large cohort of patients undergoing open maternal-fetal surgery for fMMC closure. Further study is warranted to determine the generalizability of these results.