Drinking and pregnancy don’t mix, but when are babies most vulnerable to the effects of alcohol?
The end of the first trimester appears to be the period when alcohol can wreak the most havoc on fetal development, causing physical deformities as well as behavioral and cognitive symptoms, according to research in the journal Alcoholism: Clinical & Experimental Research.
According to the March of Dimes, about 1 in 12 women admit to drinking during pregnancy, and 1 in 30 say they binge-drink, or consume five or more drinks at one sitting. Exposure to alcohol in utero leads to fetal alcohol spectrum disorders in about 40,000 newborns every year in the U.S. While adults can break down alcohol relatively safely, still-developing fetuses tend to keep more alcohol in their blood, which can hinder the development of brain and body.
Between 1978 and 2005, scientists at the University of California, San Diego worked with 992 women who provided information about how much alcohol they drank — as well as other substances they used — every three months during their pregnancies.
For every one additional drink the mothers consumed between their 43rd and 84th days of pregnancy, their babies had a 16% greater chance of being born smaller than average, which may put them at greater risk for mental and physical problems. Their infants were also more likely to have birth defects, such as a 25% higher risk of a smooth ridge linking the nose and upper lip, a 12% increased risk of an abnormally small head and a 22% greater chance of unusually thin upper lips.
While the data reinforce current guidelines that expectant moms avoid alcohol, it’s particularly difficult for those in the first days of pregnancy, especially since 50% of pregnancies in the U.S. are unplanned. That means most women may not even become aware they are pregnant until the middle or end of the first trimester.
So even women who may not be planning to become pregnant should be aware of the risks of alcohol on developing fetuses. As Tom Donaldson, president of the National Organization on Fetal Alcohol Syndrome told USA Today, “One of the challenges has been determining what are the windows of risk and the patterns in timing and quantity of alcohol use. This article very clearly demonstrates that risk begins with any use.”
The authors agree, writing that:
Based on our findings, there is no safe threshold for alcohol consumption during pregnancy with respect to selected alcohol-related physical features. Women who are of childbearing age and who are contemplating or at risk of becoming pregnant should be encouraged to avoid drinking, and women who are pregnant should abstain from alcohol throughout pregnancy.