Study: Light drinking during pregnancy may have implications for child later in life
Dec. 27, 2002

By KATHLEEN FACKELMANN
Gannett News Service

Women who drink light-to-moderate amounts of alcohol during pregnancy may put their children at risk for mild growth delays and other health problems later in life, new research suggests.

The research is preliminary and doesn’t prove that social drinking during pregnancy causes major damage to the fetus. In fact, researchers know that a woman’s body can protect the fetus to some degree from potentially damaging substances like alcohol. Still, this research raises some troubling questions about the safety of light drinking during pregnancy and the implications for the child later in life.

The studies show that:

* Pregnant women who drank as little as one drink a week during pregnancy had teens who lagged slightly behind when it came to weight and height.

* Rat pups exposed to alcohol in the womb are more likely to develop breast cancer as adults. The findings may not apply to humans. But if they do, they suggest that pregnant women who drink may put their unborn daughters at risk of developing breast cancer decades later.

The worry of potential risks from light drinking during pregnancy is real given the backdrop of studies clearly showing that women who drink heavily run the risk of delivering a baby with birth defects and brain damage. About 4,000 U.S. babies a year are born with fetal alcohol syndrome.

Drinking large amounts of alcohol during pregnancy causes mental retardation and serious growth deficits. But researcher Nancy Day and her colleagues wondered if smaller amounts of alcohol could cause more subtle problems.

“We were able to find growth deficits at very low levels — way below a drink a day,” says Day, an alcohol expert at the University of Pittsburgh School of Medicine.

Day’s team began their study in 1983 by recruiting more than 760 pregnant women. They asked the volunteers to tell them how much they drank and then kept track of the women and the kids. They later had information on 565 teenagers, who were 14 at the time.

In the October “Alcoholism: Clinical & Experimental Research,” the team reports that women who drank as little as one or two drinks a week had kids that weighed about 3 pounds less than the kids whose mothers didn’t drink. That weight difference widened the more the mothers drank during pregnancy. The researchers controlled for other factors that affected growth, such as diet.

The kids of women who drank alcohol also fell behind on other markers of growth like height and head size. The differences weren’t dramatic: These kids look normal in every way, Day says. The delays almost certainly won’t affect a child’s performance on the soccer field.

Alcohol, breast cancer link

There’s no question that alcohol, in large amounts, can hammer the developing fetal brain. Now a rat study suggests that alcohol also possibly increases the risk of breast cancer, a disease that kills 40,000 women each year in the United States.

It has been known that adult women who drink can increase their chances of developing breast cancer. That’s because drinking raises the blood levels of the hormone estrogen. This hormone tells breast cells to divide and can increase the risk that a malignant breast tumor will start to grow.

Leena Hilakivi-Clarke of the Georgetown University Medical Center in Washington, D.C., and her colleagues gave pregnant rats a daily dose of booze starting in the second trimester. The rats delivered normal-looking pups, but a close exam revealed that some had breast tissue abnormalities that can set the stage for cancer.

Next the team exposed the rats to a chemical known to cause breast cancer. Not every rat given this cancer-causing agent got cancer. But the Georgetown team found that rats with a history of alcohol exposure in the womb had twice the risk of getting a breast tumor when compared with rats that had never been exposed to alcohol.

Hilakivi-Clarke worries that the same pattern will hold true for humans. She says alcohol in the mother’s blood may leave a daughter with breast tissue that’s vulnerable to cancer-causing chemicals in the environment. The team reported their findings in October at the American Association for Cancer Research meeting in Boston.