Imaging Study Sheds New Light on Alcohol-related Birth Defects
Researchers said maternal alcohol use is the leading known and preventable cause of birth defects and mental disability in the United States and alcohol's effects can cause a range of cognitive, developmental and behavioral problems that typically become evident during childhood, and last a lifetime.
The findings are published in the online journal PLOS ONE.
In the animal-based study, researchers treated one group of mice with alcohol on their seventh day of pregnancy, a time corresponding to the third week of pregnancy in humans.
A second group of mice was treated just 36 hours later, approximating the fourth week of human pregnancy. The amount of alcohol given was large, high doses that most women wouldn't achieve unless they were alcoholic and had a tolerance for alcohol.
Near the end of pregnancy, the fetuses were then imaged at Duke University. These 3D data sets showed individual brain regions, as well as accurate and detailed facial surfaces.
The team found that the earlier alcohol exposure time elicited the classic Fetal alcohol syndrome (FAS) facial features, including characteristic abnormalities of the upper lip and eyes. What they observed in fetuses exposed just 36 hours later, however, was a surprise. These mice exhibited unique and in some cases opposing facial patterns, such as shortened upper lip, a present philtrum, and the brain, instead of appearing too narrow in the front, appeared wide.
Fetal alcohol syndrome (FAS) is at the severe end of fetal alcohol spectrum disorders (FASD). First described in 1972, FAS is recognized by a specific pattern of facial features: small eyelid openings, a smooth ridge on the upper lip (absence of a central groove, or philtrum), and a thin upper lip border. In its full-blown state, FAS affects roughly 1 in 750 live births in the U.S.
Researchers said the results of the studies show that alcohol can cause more than one pattern of birth defects, and that the type and extent of brain abnormalities-which are the most devastating manifestation of prenatal alcohol exposure-in some cases may be predicted by specific facial features.
They also concluded that alcohol can cause tremendously devastating and permanent damage at a time in development when most women don't recognize that they're pregnant.
They said study could expand the base of diagnostic criteria used by clinicians who suspect problems caused by maternal alcohol use.