Injury during pregnancy and nervous system birth defects: Texas, 1999 to 2003

BACKGROUND Case reports and series have suggested an association between injury during pregnancy and several nervous system and nervous system–related adverse fetal/neonatal outcomes. This study's purpose is to further determine if there is an association between injury during pregnancy and nervous system birth defects in infancy. METHODS Through a case–control study, the association between injury during pregnancy and nervous system birth defects was tested using the Texas Birth Defects Registry (1999–2003). Semiautomated probabilistic bias analysis was used to correct for systematic error from misclassification of injury during pregnancy. RESULTS Of the 59,750 infants eligible for this study, 4144 (6.94%) were diagnosed with a nervous system birth defect and 315 (0.53%) of the infants' mothers were injured during pregnancy. Among these 315 women, 25 (7.94%) delivered an infant with a subsequent nervous system birth defect. The adjusted odds ratio for the association between injury during pregnancy and nervous system birth defects among all study infants was 1.00; 95% confidence interval, 0.63–1.56 and 2.44; 95% confidence interval, 1.08–5.53 among breech presentation infants. Probabilistic bias analysis supported these findings. CONCLUSION No association between injury during pregnancy and nervous system birth defects was identified. Further exploration into the association among breech presentation infants is warranted. Birth Defects Research (Part A) 97:641–648, 2013. © 2013 Wiley Periodicals, Inc.