Studies Warn of Dangers of Drinking in Pregnancy

Confirm detrimental but not always obvious effects on babies

MONDAY, March 15, 2004 (HealthDayNews) -- Is it safe to drink any amount of alcohol during pregnancy?

Probably not, because maternal alcohol consumption -- whether light or heavy -- can cause harm that's evident in infancy and can continue to cause problems even into the teen years, report two new studies from the March issue of Alcoholism: Clinical and Experimental Research.

One study confirms that even small to moderate amounts of alcohol during pregnancy can cause memory and learning problems years later. The other study found that babies who had heavy prenatal alcohol exposure take longer to calm down and are slower to respond to cues in their environment than babies of mothers who imbibe less or not at all.

"The bottom line is that women should not drink during pregnancy," says the lead author of the first study, Jennifer Willford, an assistant professor in psychiatry at the University of Pittsburgh School of Medicine. "We cannot say that there is a safe level of drinking during pregnancy."

Dr. Jay Goldsmith, a neonatologist at Ochsner Clinic Foundation Hospital in New Orleans, agrees. "Fetal alcohol effects are probably more widespread than we've previously thought. Women should not be drinking in pregnancy, and more importantly, shouldn't be drinking before they get pregnant, because it's four to six weeks before you even know you're pregnant." And, he says those weeks are very important developmentally.

Willford and her colleagues collected data from a long-term study of nearly 600 children whose mothers were evaluated during each trimester of their pregnancies, and then the children were followed at regular intervals from birth to age 16. The current study looked at the children when they were 14 years old, and the researchers tested the children's learning and memory abilities.

The researchers used a test called the Children's Memory Scale, which is designed to assess learning ability in both verbal and visual-spatial areas. The test also evaluates memory function.

Light to moderate alcohol exposure during the first trimester of pregnancy was associated with memory and learning problems at 14, says Willford. Light drinking was defined as less than three alcoholic drinks per week, while moderate drinking was three drinks per week, but less than one drink per day.

Willford says the learning problems were responsible for the memory problems.

"We've shown that drinking even moderate amounts during pregnancy can have permanent effects on learning and memory," she says. "We found effects at all levels of drinking." But, she adds, the more heavily a woman drank during pregnancy, the greater the learning and memory problems were in the children.

In the second study, researchers from the Emory University School of Medicine showed 118 6-month-old infants pictures of faces and played auditory tones for them while recording changes in their heart rate and their behavioral responses.

One hundred babies were classified as low-risk and 18 were considered high-risk. Mothers of high-risk infants averaged about four drinks per day before their pregnancies and nearly two drinks per day throughout their pregnancies, compared to 1.3 drinks per day before pregnancy and less than one drink per day during pregnancy for the low-risk group. Mothers in the high-risk group were almost twice as likely to drink alone, and 35 percent had gotten into trouble because of their drinking, compared to less than 2 percent of the mothers in the low-risk group.

They found that high-risk infants took longer to respond and then had a harder time calming back down.

"If you are drinking heavily during pregnancy, how your baby responds to the environment will be slower and they'll have a harder time calming themselves down," says study author Julie Kable, an assistant professor of pediatrics at Emory.

She says from this and other research, she and her co-author, Clair Coles, theorize that prenatal alcohol exposure may disrupt the development of myelin, which then later interferes with the brain's ability to send electrical messages between nerve cells.

More information

To learn more about alcohol and its effects on pregnancy, visit the March of Dimes or the National Institute on Alcohol Abuse and Alcoholism.

SOURCES: Julie Kable, Ph.D., assistant professor, pediatrics, Emory University School of Medicine, Atlanta; Jennifer Willford, Ph.D., assistant professor, psychiatry, University of Pittsburgh School of Medicine, Pittsburgh; Jay Goldsmith, M.D., neonatalogist, Ochsner Clinic Foundation Hospital, New Orleans; March 2004 Alcoholism: Clinical and Experimental Research
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