Most of us would automatically say, “No!” But a growing number of women and their doctors feel that an occasional drink during pregnancy does no harm. A number of health professionals and pregnant women are advocating for choice and commonsense, promoting the idea that a small glass of wine for dinner is okay. In fact, a recent survey showed that one-third of women drank alcohol at some point in their pregnancy and one-fourth drank during their first trimester. Is this a good idea?
Since 1981 public health policy in the US has recommended abstinence from alcohol during pregnancy. It has become an accepted idea and is based on the physical and mental defects seen in Fetal Alcohol Syndrome caused by excessive alcohol abuse. Does this same caution apply to women who drink little or moderately? Frankly, we don’t know. There are no clinical studies on alcohol use in pregnancy for obvious ethical reasons. Much of our information is based on animal studies. Do the negative results of alcohol use on mice translate to the same problems in humans? Again, we don’t know
Let’s look at what we do know. Alcohol freely passes over the placenta in concentrations similar to that found in the mother’s bloodstream. The alcohol circulates in the fetal environment and can damage fragile fetal cells. This toxic effect would be more severe during early pregnancy when cells are dividing and developing into organs and structures. Often a woman does not know she is pregnant until 4 to 6 weeks after conception. Drinking, and especially binge drinking, during this phase of pregnancy could have serious consequences as far reaching as spontaneous abortion. Considering that slightly over 12% of all women 18 to 44 admit to occasional binge drinking, advice to limit or avoid alcohol if you are pregnant or considering a pregnancy seems wise.
Now let’s look a little further at the idea of moderate drinking during pregnancy – a small glass of wine with dinner. It probably won’t cause any damage, especially if taken with food. But, again we need to clarify this point. Women absorb alcohol more quickly than men and their blood alcohol level rises faster. It is the blood alcohol level that influences the baby’s exposure and that can be different for each woman and depend on a number of variables – large women versus small, food versus no food, drinking quickly versus sipping slowly, and wine or beer with lower absolute alcohol content versus vodka or scotch. Another important variable is the timing in pregnancy – first trimester versus third. The more developed the baby, the less likely damage may occur.
We can argue forever about how much alcohol is safe, but we just don’t know. Chronic exposure to alcohol will cause mental and physical defects in unborn babies. But lesser exposure can have more subtle effects – problems with learning, memory, problem solving, and attention; minor growth abnormalities; alterations in stress response leading to difficulty with social and emotional functioning; minor heart abnormalities; and lower birthweights.
We are not the only country to advocate for abstinence during pregnancy. A literature review done in Great Britain determined that low-moderate levels of alcohol consumption showed no consistent harm to pregnancies. The researchers, however, felt the evidence was so weak they concluded that drinking even small amounts during pregnancy could not be considered safe. In Australia, national guidelines recommend that women who choose to drink alcohol during pregnancy should have less than 7 drinks in any week and no more than 2 drinks on any day, and they should never become intoxicated. But they conclude the recommendation with, “We do not know what level of alcohol exposure is safe and pregnant women can only be advised to abstain.” A Harvard study would back up this advice because it concluded that temptation to drink was the best predictor of prenatal drinking frequency. Not drinking removes some of the temptation to drink and the need to make judgments on how much to drink. Or, as the title of a French research article on alcohol use in pregnancy says, “No, let’s not advise patients to drink wine. “
And, one final thought to consider – moderate alcohol consumption, as little as 5 or fewer drinks a week, has been shown to decrease fertility. Women who drink regularly may have difficulty conceiving.