Infant Hair Sample Betrays Maternal Drinking During Pregnancy
But doctors divided over value of test
WEDNESDAY, Dec. 18, 2002 (HealthDayNews) -- Testing infant hair could help doctors identify babies at risk for fetal alcohol syndrome because their mother drank during pregnancy.
Physicians who suspect a pregnant woman was drinking or using drugs now look for signs of those substances in the early feces, or meconium, of her newborn. However, meconium quickly passes through the body and is available for two or three days after birth at most.
The new test, first used on newborns by Canadian researchers, detects molecules called fatty acid ethyl esters. It can, in theory, pick up evidence of alcohol exposure for as long as three months after birth, the researchers say.
Little can be done for a child exposed to excessive alcohol in the womb. But knowing a child might be vulnerable to fetal alcohol syndrome could be of value to child welfare and law enforcement officials who might want to take action against the mother.
Of course, not all babies are born with hair, so for these infants the new test wouldn't be useful. But for the rest, it could significantly widen the window during which alcohol exposure screening is effective, says research leader Dr. Gideon Koren, of Toronto's Hospital for Sick Children.
"I think the fact that you can measure [alcohol exposure] in hair is very big news," says Koren, co-author of a research letter describing the technique in a woman and her baby girl who tested positive for both cocaine and alcohol. The letter appears in tomorrow's issue of The New England Journal of Medicine.
The test used mass spectroscopy to analyze the chemical makeup in small samples of hair. It found the baby girl's fatty acid ethyl ester concentrations -- which reflect maternal alcohol breakdown -- were about six times lower than her mother's but detectable nevertheless. The woman had said she was a "social" drinker during pregnancy, suggesting that newborns exposed to greater amounts of alcohol should have stronger signs of it in their hair.
Koren and his colleagues haven't looked yet for indications of alcohol in infant hair as far out as three months. However, they've done so successfully for other substances, including cocaine, nicotine and marijuana, he says.
The hair test is still "cumbersome," says Koren, director of the Motherisk program, a counseling and testing service for pregnant and nursing women. Once demand for the screening increases, he expects it will become quicker and less costly.
A larger concern is correlating levels of ethyl esters, either in hair or meconium, with the risk of fetal alcohol syndrome. No one has been able to do so to date.
Another potential problem: Every fetus is exposed to trace amounts of alcohol from the mother through the normal breakdown of sugars. However, at least in meconium testing, the amounts present in the newborns of women who drink during pregnancy are 10 to 100 times higher than the normal level, Koren says.
Fetal alcohol syndrome affects between 0.3 and 2.2 American babies per 1,000, or between 1,200 and 8,800 newborns a year, according to the U.S. Centers for Disease Control and Prevention (CDC). Alcohol exposure during pregnancy can lead to birth defects as well as severe mental and behavioral problems, including low IQ and attention-deficit disorder. These symptoms don't generally appear for several years -- long after any neonatal test would be helpful.
Fewer women drink during pregnancy than did in the past, the CDC says. However, the number who report consuming at least seven drinks a week and five or more drinks at a sitting jumped fourfold between 1991 and 1995.
Since fetal alcohol exposure during the first three to eight weeks of development is linked to birth defects, many women drink before they know they're pregnant.
Some states require hospitals to notify child welfare officials if a mother admits to drinking during pregnancy or if she tests positive for alcohol or drug use. None requires testing meconium for all newborns.
Dr. Cynthia Bearer, a neonatologist at Case Western Reserve University in Cleveland and an expert on fetal exposures to toxic substances, says she doesn't believe the hair test will replace meconium screening.
"Every baby has meconium and a lot of babies don't have hair. And a lot of moms don't like it if you cut their baby's hair off," she says.
Eventually, Bearer says, she'd like to see meconium testing be routine in delivery wards, not just for drugs and alcohol but other prenatal exposures as well, such as chemicals in the environment. "You'd get a picture of the exposures, and maybe have an intervention" to prevent or reverse harm to the infant, she says.
The only step that effectively discourages women from drinking during pregnancy is to educate those who've already done so before about the risks to their future pregnancies, Bearer says. Warning labels on alcohol and at bars and liquor stores don't seem to be more than a temporary deterrent, and only with more educated women, she says.
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