Maternal smoking and craniosynostosis.

To investigate a possible association between maternal smoking during pregnancy and craniosynostosis (premature closure of one or more of the cranial sutures), a study was conducted using Swedish health registries. Infants with craniosynostosis (n = 304) without a known chromosome anomaly were selected among 1,413,811 infants born between 1983-1996 with known smoking exposure in early pregnancy. A statistically significant association between maternal smoking and craniosynostosis was found (adjusted odds ratio (OR), 1.45; 95% confidence interval (CI), 1.13-1.87), but this association was only valid for isolated defects (OR, 1.67; 95% CI, 1.27-2.19). For associated craniosynostosis (malformation syndromes included), a negative (nonsignificant) association with maternal smoking was indicated instead. For isolated craniosynostosis (all types), a dose-dependent effect of maternal smoking was indicated (OR and 95% CI for smoking <10 cigarettes/day, 1.45 (1.04-2.02); OR and 95% CI for smoking >/=10 cigarettes/day, 2.12 (1.50-2.99)), but was not statistically significant. Among the different types of craniosynostosis, premature closure of the sagittal suture showed the strongest association with maternal smoking (OR, 1.48; 95% CI, 1. 02-2.14), whereas for coronal suture defects, no association with maternal smoking could be detected (OR, 1.02; 95% CI, 0.47-2.21). As no obvious confounders were detected, the present study supports an earlier report of an association between maternal smoking during pregnancy and at least some types of craniosynostosis. Copyright 1999 Wiley-Liss, Inc.