RESUMO
OBJECT: The authors undertook this study to assess the effect of preterm delivery with respect to neural protection in a congenital myelomeningocele (MMC) mouse model. METHODS: After confirmation of pregnancy in 15 female mice, a congenital MMC model was produced by administration of retinoic acid on the 7th day of gestation. The pregnant mice underwent cesarean sections on Days 15 (n = 5, Group E15), 17 (n = 5, Group E17), and 19 (n = 5, Group E19). Histological analyses were conducted on the lumbar defect and on the craniocervical junction in all fetuses with MMC. RESULTS: Fetuses in Group E19 showed the most significant injury to neural tissue of the spinal cord at the MMC area followed by those in Group E17, with Group E15 being the least affected. All groups exhibited a degree of Chiari malformation; Group E19 was the most affected, followed by Group E17, and Group E15 was the least affected. CONCLUSIONS: Development of both Chiari malformation and exposed spinal cord injury are progressive during gestation. Preterm delivery in this mouse model of congenital MMC may minimize the degree of injury to the spinal cord neural tissue and the degree of Chiari malformation.