By Catherine Donaldson-Evans of AOL Health
Pregnant women can have a drink or two a week without worrying about hurting their unborn babies, according to a new study.
Light drinking during pregnancy won't do any harm to the fetus and may actually be beneficial for the development of the child, researchers in the U.K. found.
"There hasn't been rigorous research to look at the lower end of the drinking spectrum," said lead researcher Yvonne Kelly, an epidemiologist at University College London, according to Discovery News. "Regardless of the emotive issues, we wanted to look at the science."
But excessive consumption of alcohol is another story.
"Heavy binge drinking has been linked for a long time with difficulties for mothers and the children born to them," Kelly said.
The research tracked children for five years after they were born and found that those whose mothers had a little alcohol during pregnancy tended to advance more developmentally than those whose moms abstained.
"My belief was always that very light drinking was not associated with a bad outcome," Dr. Marjorie Greenfield, the division chief of general obstetrics and gynecology at University Hospitals Case Medical Center, told AOL Health. "The problem was there wasn't a study to prove it."
The authors used a long-term survey that has followed more than 18,500 children since birth. When the babies were 9 months old, their mothers were questioned about how much they drank when they were pregnant. Because the study was conducted in the U.K., where light drinking during pregnancy isn't frowned upon, the researchers believe the women were more forthcoming about their alcohol use than they would have been in other countries.
The children were given several tests measuring their mental, emotional and behavioral development. They repeated the exercises when they were 3 years old and 5 years old.
The moms were categorized by how much they drank: those who never drank, whether they were pregnant or not; those who stopped drinking during pregnancy; those who had one to two drinks a week; those who had up to six drinks a week; and those who consumed more than six drinks a week. A drink was defined as a half-pint of beer, a small glass of wine or one serving of liquor.
The findings, published in the Journal of Epidemiology and Community Health, revealed that the kids of heavy drinkers performed the worst on the tests, confirming previous research showing that unborn babies who have extensive exposure to alcohol can suffer nerve and brain damage.
But surprisingly, the children of moms who never drank at all performed almost as badly on the exercises.
Those born to light pregnant drinkers showed no signs of developmental or learning difficulties through age 5. Boys tended to do better on vocabulary and pattern design tests if their mothers did drink a little alcohol while they were pregnant.
"There is no detectable risk associated with light or moderate drinking during pregnancy," Fred Bookstein, a fetal alcohol specialist at the University of Washington in Seattle and the University of Vienna, told Discovery News.
Bookstein theorizes that women who cut back on alcohol during pregnancy may be more conscientious about their health and more medically educated, even if they still have a drink here and there.
Those who drink lightly while they're expecting may also be more relaxed, which may offset the negative effects stress can have on the fetus, Kelly said.
"If you're somebody who can have one drink and stop, then it's okay," Greenfield said. "If you're somebody who has ever had a problem with drinking, you shouldn't drink during pregnancy."
She said those who already live a healthy lifestyle aren't at risk of harming the fetus.
"I hate when we treat pregnancy like some fragile state -- like everything you do should be about the baby," said Greenfield. "In that sense, I like to tell people that as long as their normal life is healthy, they're not going to cause any problems."