HomeHealth Topics A to ZHow much is too much? Alcohol use in pregnancy.
Health Topics

How much is too much? Alcohol use in pregnancy.

By Susan Mitchell, MD

A recent article published in the Journal of the American Medical Association (JAMA), “Prevalence of Fetal Alcohol Spectrum Disorders in 4 US Communities”, indicates that the number of children affected by their mother’s drinking alcohol in pregnancy is likely higher than we previously thought. Previous estimates were that the incidence was about 10 per 1000 children (1%), but the new study published in JAMA suggests the incidence could be as high as 5% or even 10%. What does this mean for women who are pregnant or trying to become pregnant?

No one knows how much alcohol should be considered “safe” in pregnancy. Binge drinking (>4 drinks on one occasion) and drinking throughout pregnancy are generally considered dangerous. We know that women who don’t drink at all in pregnancy are not at risk. But where between none and daily can be considered “safe”?

The only answer is that no one knows. This is extremely difficult to study, partly because most studies ask women how much alcohol they consume in pregnancy, and it is likely that women are not always providing accurate answers. Studies have defined “prenatal alcohol exposure” as six or more drinks a week for two weeks or more, and/or three or more drinks per occasion on two or more occasions. So is one drink a month okay? What about four or ten?

Alcohol crosses the placenta and goes to the baby. Fetal blood alcohol levels are approximately as high as mom’s levels within two hours. So if a mom is “buzzed” on alcohol, so is the baby. If a mom is drunk, the baby is too. But a baby does not eliminate alcohol like an adult. Much of the alcohol affecting the fetus is excreted by the baby back into the amniotic fluid and re-swallowed by the baby again and again. That means that long after a mom is feeling no more affects from the alcohol she has consumed, her baby is being re-exposed for a much longer period of time, essentially marinating in alcohol.

This re-exposure to alcohol can affect the baby in a variety of ways:  

  • The baby’s physical features, such as the appearance of the baby’s face.
  • The baby’s neurocognitive and behavioral development.
  • It can permanently affect a child’s impulse control and judgment, memory, and learning.
  • It significantly increases the risk of stillbirth.

The more you drink, the more the baby is likely to be affected. Daily drinking and binge drinking may be particularly dangerous. How much is too much? A better question is: Why risk harming your baby at all?

Common questions:

  1. I had a few drinks at a wedding before I knew I was pregnant. Did I harm my baby? Probably not. It is common for women to drink alcohol before they know they are pregnant and most of the time, it does not seem babies are affected. Don’t beat yourself up about that glass of wine you had with dinner, or those couple of beers you had out with friends. But now that you know you are pregnant, stop drinking.

  2. I’m trying to conceive. Is it okay to drink? It’s better not to drink. Because we don’t know for certain how much drinking in early pregnancy could affect a baby’s development, it’s safer not to drink at all.

  3. I enjoy a glass of wine now and then with dinner. Can I continue drinking maybe once or twice a week? This amount of drinking might not affect your baby, or it might. We just don’t know. Would you give your newborn or toddler alcohol a few times a week? Probably not. It’s not recommended to expose your unborn baby to alcohol either.

  4. I drink regularly, 2-3 drinks most days, and on weekends maybe 4-5 drinks a day. I don’t think my alcohol consumption is a problem for me. Is it really a big deal if I continue? It is a big deal. This amount of drinking, even for women who don’t feel they have a problem with alcohol, has clearly been shown to significantly increase the risk of harm to their babies. Talk to your doctor about your alcohol consumption, and let him or her know if you need help quitting.

Learn more about:
Obstetrics and Gynecology
Receive more health tips and DMG news right in your inbox!
Sign up for the Live Life Well newsletter