Maternal cigarette smoking and the associated risk of having a child with orofacial clefts in China: A case-control study

Background: We investigated whether maternal and paternal cigarette smoking during early pregnancy could increase the risk of delivering an infant with an orofacial cleft. Methods: A case-control study was carried out in China. 304 infants born with an isolated nonsyndromic oral cleft and 453 non-malformed controls were recruited as participants and their exposure to smoke plus family history data were collected. Results: The relative odds ratios of maternal smoking to cause an orofacial cleft in infant increased for 3.30 (95% CI, 1.17-9.33) in CLO and 3.12 (95% CI, 1.24-7.84) in CLP from 1 to 10 cigarettes per day before pregnancy. The unadjusted odds ratio is 3.64(95% Cl, 1.01-13.19) and the adjusted OR is 7.00 (95% Cl, 1.44-34.13) in CLO from 1 to 10 cigarettes during the first trimester. Paternal smoking in the peri-conceptional period was strongly associated with all subtypes of CLR The association with medium ETS (2-6 h) at home or at work was strongest for infants with all OFCs in the periconceptional period from 1 month before pregnancy through the end of the first trimester. Conclusion: This study confirmed the modest association between maternal smoking and orofacial clefts. (C) 2010 European Association for Cranio-Maxillo-Facial Surgery.