Study: no connection between drinking alcohol early in pregnancy and birth problems

In a new study sure to raise hackles and controversy, an international team of researchers is reporting that pregnant women who drink alcohol during the first trimester of pregnancy and possibly beyond aren’t putting their babies at risk for premature birth or low birth weight, or themselves at risk for high blood pressure complications during pregnancy.

Dr. Fergus McCarthy and colleagues from Ireland, England, New Zealand, and Australia compared birth outcomes among 5,628 women who were pregnant for the first time between 2004 and 2011. More than half of them reported drinking alcohol during the first three months of pregnancy. Some (19%) reported occasionally drinking alcohol. Twenty-five percent reported low alcohol consumption, or three to seven drinks per week (“a drink” defined as a glass of wine or a little less than a 12-ounce bottle of beer). Another 15% reported having more than seven drinks per week.

Rates of premature birth, babies with low birth weight or small size, and preeclampsia—a potentially life-threatening condition in which a pregnant woman develops high blood pressure—were similar across the alcohol consumption categories

The study did not measure the effect of drinking alcohol during pregnancy on development after birth. The results were published online ahead of print in the October issue of the journal Obstetrics & Gynecology.

For the past few decades, women have been urged to avoid alcohol during pregnancy. Respected medical societies like the American College of Obstetricians and Gynecologists and the United Kingdom’s Royal College of Obstetricians and Gynaecologists Women both say women shouldn’t drink any alcohol during pregnancy. The main reason for this is that heavy use of alcohol during pregnancy has been linked to a long-term and irreversible condition known as fetal alcohol syndrome (FAS).

Babies with FAS may be born early. They are often underweight and don’t grow well. Some have characteristic facial features like a thin upper lip and small eye openings, or the small vertical groove between the upper lip and the nose may be flattened. Other physical signs that go along with fetal alcohol syndrome include a small head, short nose, and problems with the way the heart or the joints are formed.

Children with FAS are slower to learn language skills than other kids. When they reach school age they often have learning disabilities and difficulty with attention, memory and hyperactivity. They are more likely to have poor coordination and a hard time with problem-solving. And some have trouble making friends and relating to other kids. All of which can make school a really difficult time.

Despite this clear advice, up to half of women drink alcohol during pregnancy.

How clear is the medical evidence supporting strict abstinence from alcohol during pregnancy? Not very strong. And recent studies suggest pregnant women who have an occasional drink don’t harm themselves or their baby. A 2012 Danish study, for example, found that low to moderate alcohol consumption during pregnancy did not affect executive functioning among 5-year-olds. Executive functioning is a catchall term that describes the ability to perform activities such as planning, organizing, strategizing, remembering details, and managing time.

Keep in mind that moderate drinking means no more than one drink per day.

Since it’s not clear how much alcohol it takes to cause problems, the best advice remains the same: women should avoid alcohol if they are pregnant or might become pregnant.

Many women are pregnant for a while before they know it. Does their alcohol consumption during the time they were pregnant but didn’t realize it doom their child? No. They almost surely did no harm to their unborn children.

Not everyone agrees that you should avoid all alcohol if you are trying to get pregnant. Some respected health agencies, like the United Kingdom’s Department of Health, indicate that having one alcoholic beverage a couple times per week during pregnancy is okay.

Looking at the evidence, a strict recommendation to have zero alcohol during pregnancy seems extreme. Will there be consensus about whether it’s safe for a pregnant woman to have a glass of wine or a beer once or twice a week? I don’t think we will see that any time soon.