Cigarettes Smoking can Increase Cleft Lip Risk
Cleft lip and palate are fairly serious birth defects. They are the fourth most common congenital abnormalities, affecting about one in 700 newborns.
A new study showed that pregnant women who smoke or regularly breathe second-hand smoke may be raising the odds that their baby will be born with a cleft lip. About one in every 600 U.S. babies is born with a cleft lip or cleft palate.
Cleft lip and cleft palate arise when the tissues that form the roof of the mouth and the upper lip do not fuse properly, sometime between the fifth and ninth week of pregnancy.
Cleft lip and cleft palate can arise in newborns because of the lack of both copies of the gene, called GSTT1. When the gene is missing, a baby is unable to remove the toxins that may be transferred across the placenta when the mother smokes.
Norwegian researchers found that women who smoked more than 10 cigarettes per day during their first trimester were nearly twice as likely to have a baby with a cleft lip as nonsmokers were.
The new findings add that to that evidence, and also suggest that smoking affects the odds of cleft lip regardless of certain genes.
Dr. Rolv T. Lie, of the University of Bergen in Norway, and his colleges assessed 1,336 infants - 573 of whom had an oral cleft - for several variations in "detoxification" genes believed to help the body rid itself of tobacco smoke toxins. In most cases, their parents were assessed as well.
However, Lie’s team found no evidence that these genes affected the cleft lip risk connected with maternal smoking and passive smoking.
