There is a positive association between maternal smoking during the first trimester of pregnancy and orofacial clefts, according to a study in the July issue of Cleft Palate-Craniofacial Journal.
Subjects in the Scottish study were 190 children born with an orofacial cleft between Sept. 1, 1997, and Jan. 31, 2000, and 248 matched controls. To investigate the association between maternal smoking and orofacial clefts, researchers used a structured interview to assess the subjects’ mothers’ exposure to tobacco smoke.
Researchers found that maternal smoking during the first trimester of pregnancy increased the subject’s odds of having cleft lip with or without cleft palate by 1.9-fold and the odds of having cleft palate by 2.3-fold.
The study’s finding of a small increase in the risk of a subject’s developing cleft lip with or without cleft palate when the mother smoked during pregnancy is in line with findings from previous studies. However, their finding of an increased risk for cleft palate was in contrast with finding from some previous studies.
Researchers also found evidence that the level of risk for both types of orofacial clefts was related to the amount the mothers smoked. In addition, the data indicated that maternal passive smoking increased the subject’s risk of developing orofacial clefts. The study, however, lacked the statistical power to detect or exclude such an effect with confidence.
Researchers suggest that it may be useful to incorporate information on the effects of maternal smoking on orofacial clefts into public health campaigns on the consequences of maternal smoking.
