1: Subsequent pregnancy outcomes after open maternal-fetal surgery for fetal myelomeningocele closure

Abstract

Limited data is available regarding subsequent pregnancy outcomes after maternal-fetal surgery via hysterotomy. The objective of this study was to ascertain obstetric risk in subsequent pregnancies after open fetal surgery (OFS) for myelomeningocele (MMC) closure. An international multicenter registry (North American Fetal Therapy Network/ fMMC Consortium Outcomes Registry) was created to track and report maternal, obstetric, fetal/neonatal and subsequent pregnancy outcomes following maternal-fetal surgery for MMC. Subsequent pregnancy outcome variables were collected via maternal questionnaire. Data are collected from each center and entered into a combined de-identified dataset using REDCap. Subsequent pregnancy outcomes data were analyzed using descriptive statistics. Centers participating in the registry obtained local IRB approval and executed data use agreements. A total of 52 subsequent pregnancies in 40 women were reported after OFS for MMC. Of these 40 women, 32 had 1 subsequent pregnancy, 5 women had 2, 2 women had 3, and 1 woman had 4 pregnancies after OFS, all singleton gestations. There are 10 that are ongoing or have missing outcome data. The live birth rate among those with complete data was 63%. Among the 52 subsequent pregnancies, 7 (13.5%) resulted in miscarriage < 20 weeks. Of the 35 pregnancies progressing > 20 weeks EGA, uterine rupture occurred in 11.4% (4/35) and OFS uterine incision thinning/dehiscence was described in 8.6% (3/35) at delivery. The mean GA at uterine rupture was 29 weeks (range 26-32); Two fetal deaths were reported as a result of uterine rupture. Placenta accreta was reported in a single case. Among live births, the mean GA at delivery was 36.2 weeks (range 26.4-38.4). Blood transfusion at delivery was required in 11.1%. All patients delivered via cesarean with 89.2 % via a low transverse uterine incision. Recurrence of fetal spina bifida was noted in 2 pregnancies. The risk of uterine rupture or dehiscence, with its associated risk of fetal morbidity and mortality, in subsequent pregnancies after open fetal surgery is significant. This risk should be included in the pre-operative counseling for patients who are candidates for maternal-fetal surgery. The risk for abnormal placentation requires additional investigation. Guidelines for management of pregnancies following OFS should be developed to address these risks.