Tobacco smoking and oral clefts: a meta-analysis

Abstract

Objective: To examine the association between maternal smoking and non-syndromic orofacial clefts in infants.

Methods: A meta-analysis of the association between maternal smoking during pregnancy was carried out using data from 24 case-control and cohort studies.

Findings: Consistent, moderate and statistically significant associations were found between maternal smoking and cleft lip, with or without cleft palate (relative risk 1.34, 95% confidence interval 1.25-1.44) and between maternal smoking and cleft palate (relative risk 1.22, 95% confidence interval 1.10-1.35). There was evidence of a modest dose-response effect for cleft lip with or without cleft palate.

Conclusion: The evidence of an association between maternal tobacco smoking and orofacial clefts is strong enough to justify its use in anti-smoking campaigns.