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.

Keywords

• Smoking/adverse effects
• Cleft lip/etiology
• Cleft lip/epidemiology
• Cleft palate/etiology
• Cleft palate/epidemiology
• Pregnancy
• Infant
• Newborn
• Dose-response relationship
• Drug
• Meta-analysis
• Case-control studies
• Cohort studies