Women who binge-drink early in pregnancy are more likely to have babies with cleft lip, cleft palate or both, a Norwegian study says.
Binge drinking is defined as drinking five or more drinks in one sitting. Some women in the study did this at least once during the first trimester (13 weeks) of pregnancy. They were more than twice as likely as others to have a baby with cleft lip, cleft palate or both. Women who binge-drank more than twice were three times as likely to have a baby with one of these defects.
Researchers from the National Institute of Environmental Health Sciences did the study. They compared 573 mothers of babies with these birth defects and 763 other mothers. The second group was randomly selected from all live births in the country between 1996 and 2002.
Norway's rate of cleft lip and cleft palate is one of the highest in Europe.
According to a study author, the research shows that drinking a lot of alcohol at once increases the risk of birth defects. But this does not occur with frequent drinking of small amounts. So a woman who drank six drinks at one sitting would be at higher risk than a woman who had one drink a day for six days.
"The greater the blood alcohol concentration, the longer the fetus is exposed," Lisa A. DeRoo, Ph.D., said in a press release. "A single binge during a critical period of an infant's development can be harmful."
Last month, the same group of researchers also found that maternal smoking affected cleft risk. Smoking in the first trimester doubled an infant's risk for cleft lip, and for cleft lip and palate combined.
Cleft lip happens when the left and right sides of the upper lip do not fuse. In cleft palate, the left and right sides of the roof of the mouth (palate) do not fuse. This leaves a hole in the roof of the mouth.
Cleft lip and cleft palate are formed during the fifth to seventh weeks of pregnancy. Possible causes include a lack of folic acid, infections, smoking, and taking certain drugs, such as anti-seizure drugs. Surgery usually can correct clefts. Children with cleft palate sometimes have missing or abnormally shaped teeth.
The binge-drinking study appears in the online version of the American Journal of Epidemiology. It was published July 30.