[Neural tube defects and associated factors in liveborn and stillborn infants].

Objectives: To evaluate the prevalence and factors associated to neural tube defects in liveborn and stillborn infants delivered at the Hospital das Clínicas, UFMG, from January 8, 1999 to July 31, 2000.

Methods: This is a descriptive study, based on a database, according to the Latin-American Collaborative Study of Congenital Malformation (ECLAMC) rules. Reports on liveborn and stillborn infants with congenital anomalies were prepared including information about morphological description, necropsy results, complementary exams, family, social and pregnancy histories and other clinical data. Each malformed liveborn infant originated a control of the same sex, without malformations. The liveborn and stillborn infants with neural tube defects delivered during that period were classified according to their defect and the presence or absence of associated defects. The liveborn and stillborn infants with neural tube defects were compared to newborns without neural tube defects according to their weight and sex and their mother's age and parity. Epi-Info 6.0 Program was used for the statistical analysis of the results.

Results: The prevalence of neural tube defects was 4.73 to 1,000 deliveries (89:18,807); it was significantly higher among stillborn infants (23.7:1,000) than among liveborn infants (4.16:1,000), p < 0.001. Neural tube defects were more often found among low weight liveborn infants (< or = 2,500 g), p < 0.001 and less frequently among women who had had more than three gestations, p = 0.007. No association was found regarding newborn's sex or maternal age. There was no association with newborn's sex and weight, maternal parity or age among stillborn infants. The most common neural tube defects were myelomeningocele (47.2%), anencephaly (26.9%) and encephalocele (16.9%). The defects were found as isolated anomalies in 71.1% of the liveborn and 38.5% of the stillborn infants; they were part of a syndrome in 9.2% (liveborn) and 7.7% (stillborn).

Conclusion: The neural tube defect prevalence found in this study was higher than the one described in international and Latin-American literature.