Reducing perinatal complications and preterm delivery for patients undergoing in utero closure of fetal myelomeningocele: further modifications to the multidisciplinary surgical technique

OBJECT.: As more pediatric neurosurgeons become involved with fetal myelomeningocele closure efforts, examining refined techniques in the overall surgical approach that could maximize beneficial outcomes becomes critical. The authors compared outcomes for patients who had undergone a modified technique with those for patients who had undergone fetal repair as part of the earlier Management of Myelomeningocele Study (MOMS).

Methods: Demographic and outcomes data were collected for a series of 43 delivered patients who had undergone in utero myelomeningocele closure at the Fetal Center at Vanderbilt from March 2011 through January 2013 (the study cohort) and were compared with data for 78 patients who had undergone fetal repair as part of MOMS (the MOMS cohort). For the study cohort, no uterine trocar was used, and uterine entry, manipulation, and closure were modified to minimize separation of the amniotic membrane. Weekly ultrasound reports were obtained from primary maternal-fetal medicine providers and reviewed. A test for normality revealed that distribution for the study cohort was normal; therefore, parametric statistics were used for comparisons.

Results: The incidence of premature rupture of membranes (22% vs 46%, p = 0.011) and chorioamnion separation (0% vs 26%, p < 0.001) were lower for the study cohort than for the MOMS cohort. Incidence of oligohydramnios did not differ between the cohorts. The mean (± SD) gestational age of 34.4 (± 6.6) weeks for the study cohort was similar to that for the MOMS cohort (34.1 ± 3.1 weeks). However, the proportion of infants born at term (37 weeks or greater) was significantly higher for the study cohort (16 of 41; 39%) than for the MOMS cohort (16 of 78; 21%) (p = 0.030). Compared with 10 (13%) of 78 patients in the MOMS cohort, only 2 (4%) of 41 infants in the study cohort were delivered earlier than 30 weeks of gestation (p = 0.084, approaching significance). For the study cohort, 2 fetal deaths were attributed to the intervention, and both were believed to be associated with placental disruption; one of these mothers had previously unidentified thrombophilia. Mortality rates did not statistically differ between the cohorts.

Conclusions: These early results suggest that careful attention to uterine entry, manipulation, and closure by the surgical team can result in a decreased rate of premature rupture of membranes and chorioamnion separation and can reduce early preterm delivery. Although these results are promising, their confirmation will require further study of a larger series of patients.