Smoking and Pregnancy

English researchers confirmed previous studies linking smoking during pregnancy to an increased occurrence of cleft palate – a birth defect characterized by a split or opening in the roof of the mouth; cleft lip is where there is failure of the upper lip to completely join. In this recent study, maternal smoking during the first trimester of pregnancy increased the odds of cleft lip with or without cleft palate by 1.9 fold and the risk of cleft palate by 2.3 fold. Moreover, there was evidence that passive smoking also raised the risk of these and other orofacial cleft defects.