When a pregnant woman drinks alcohol, the alcohol travels through her blood and into the baby's blood, tissues, and organs. Alcohol breaks down much more slowly in the baby's body than in an adult. That means the baby's blood alcohol level remains increased longer than the mother's. This can harm the baby and can sometimes lead to lifelong damage.

DANGERS OF ALCOHOL DURING PREGNANCY

Drinking a lot of alcohol during pregnancy can lead to a group of defects in the baby known as fetal alcohol syndrome. Symptoms can include:

• Behavior and attention problems
• Heart defects
• Changes in the shape of the face
• Poor growth before and after birth
• Poor muscle tone and problems with movement and balance
• Problems with thinking and speech
• Learning problems

These medical problems are lifelong and can range from mild to severe.

Complications seen in the infant may include:

• Cerebral palsy
• Premature delivery
• Pregnancy loss or stillbirth

HOW MUCH ALCOHOL IS SAFE?

There is no known "safe" amount of alcohol use during pregnancy. Alcohol use appears to be the most harmful during the first 3 months of pregnancy; however, drinking alcohol anytime during pregnancy can be harmful.

Alcohol includes beer, wine, wine coolers, and liquor.

One drink is defined as:

• 12 oz of beer
• 5 oz of wine
• 1.5 oz of liquor

How much you drink is just as important as how often you drink.

• Even if you don't drink often, drinking a large amount at one time can harm the baby.
• Binge drinking (5 or more drinks on one sitting) greatly increases a baby's risk of developing alcohol-related damage.
• Drinking moderate amounts of alcohol when pregnant may lead to miscarriage.
• Heavy drinkers (those who drink more than 2 alcoholic beverages a day) are at greater risk of giving birth to a child with fetal alcohol syndrome.
• The more you drink, the more you raise your baby's risk for harm.

DO NOT DRINK DURING PREGNANCY

Women who are pregnant or who are trying to get pregnant should avoid drinking any amount of alcohol. The only way to prevent fetal alcohol syndrome is to not drink alcohol during pregnancy.

If you did not know you were pregnant and drank alcohol, stop drinking as soon as you learn you are pregnant. The sooner you stop drinking alcohol, the healthier your baby will be.

Choose nonalcoholic versions of beverages you like.

If you cannot control your drinking, avoid being around other people who are using alcohol.

Pregnant women with alcoholism should join an alcohol abuse rehabilitation program. They should also be followed closely by a health care provider.

The following organization may be of help:

• Substance Abuse and Mental Health Services Administration -- 1-800-662-HELP (4357) www.findtreatment.gov
• National Institute on Alcohol Abuse and Alcoholism -- www.rethinkingdrinking.niaaa.nih.gov/about.aspx

Drinking alcohol during pregnancy; Fetal alcohol syndrome - pregnancy; FAS - fetal alcohol syndrome; Fetal alcohol effects; Alcohol in pregnancy; Alcohol related birth defects; Fetal alcohol spectrum disorders

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Prasad M, Metz TD. Substance use disorder in pregnancy. In: Landon MB, Galan HL, Jauniaux ERM, et al, eds. Gabbe's Obstetrics: Normal and Problem Pregnancies. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 8.

Smid MC, Terplan M. Substance use and addiction in pregnancy and the postpartum period. In: Lockwood CJ, Copel JA, Dugoff L, et al, eds. Creasy and Resnik's Maternal-Fetal Medicine: Principles and Practice. 9th ed. Philadelphia, PA: Elsevier; 2023:chap 68.

Updated by: LaQuita Martinez, MD, Department of Obstetrics and Gynecology, Emory Johns Creek Hospital, Alpharetta, GA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.