(613) Surgery-To-Delivery Interval: Critical Predictor of School Age Neurodevelopmental Functioning in Prenatally Repaired Myelomeningocele

To evaluate the association between the prenatal surgery-to-delivery interval—the time between prenatal fetal myelomeningocele (fMMC) repair and delivery—and long-term neurodevelopmental outcomes, ascertained at school age.

Study Design:

This was a secondary analysis of the prenatal fMMC repair arm of the Management of Myelomeningocele Study (MOMS) using data provided by the National Institutes of Health (NIH). The primary exposure was prenatal surgery-to-delivery interval, dichotomized as ≤62 days (lowest quartile) vs. >62–110 days. Outcomes included validated neurodevelopmental assessments, need for additional neurosurgical procedures, and independent walking. Bivariate analyses used Fisher’s exact and Wilcoxon rank-sum tests. Linear regression, adjusted for covariates (p< 0.05), assessed associations between exposure and Vineland scores, the primary MOMS2 outcome.

Results:
Of 72 participants, 19 (26.4%) were in the shortest interval group and 53 (73.6%) in the longer interval group. At 10 years, children in the shorter interval group had lower standard scores in Vineland II communication (89.1 vs. 95.6, p=0.03), daily living skills (82.7 vs. 88.7, p=0.03), KBIT verbal (95 vs. 103, p=0.03), reading performance (92.2 vs. 103, p=0.006), and word generation (6.2 vs. 8.6, p< 0.001). Independent ambulation was also less frequent (6.7% vs. 35.1%, p=0.05). After adjusting for key covariates and gestational age via residual analysis, the interval was no longer significantly associated with Vineland II scores or ambulation. However, in a model adjusting only for residual gestational age, a longer interval remained significantly associated with higher Vineland Adaptive Behavior Composite standard scores (adjusted coefficient: 0.11 [95% CI: 0.006, 0.22], p=0.04).


Conclusion:
Shorter intervals between prenatal fMMC repair and delivery are linked to worse cognitive and functional outcomes in certain domains at 10 years. While this association weakens after full covariate adjustment, it remains significant when adjusting only for gestational age—suggesting an independent effect of pregnancy duration.