What effect does alcohol have on a fetus?

A woman who drinks alcohol while she is pregnant may harm her unborn baby (fetus). Alcohol can pass from the mother’s blood into the baby’s blood. It can damage and affect the growth of the baby’s cells. Brain and spinal cord cells are most likely to have damage.

The term "fetal alcohol spectrum disorder" (FASD) describes the range of alcohol effects on an unborn child. The problems range from mild to severe. Alcohol can cause a child to have physical or mental problems that may last all of his or her life.

The effects of alcohol can include:

• Odd facial features. A child may have a small head, flat face, and narrow eye openings. It may be hard to pick out one trait, but in general, a child's head and face just don't look right. This gets more obvious by age 2 or 3.
• Growth problems. Children who were exposed to alcohol in the womb may be smaller than other children of the same age.
• Learning and behavior problems.
• Birth defects. Problems can occur that involve parts of the body such as the eyes, ears, heart, bones, or urinary tract.

Heavy alcohol use during pregnancy can also lead to miscarriage, stillbirth, or a baby being born early.

How much alcohol is safe?

When a pregnant woman drinks alcohol, so does her baby. Heavy drinking (5 or more drinks on at least one occasion) during pregnancy can severely affect an unborn child. Studies do not yet show if it is safe for a pregnant woman to drink a small amount of alcohol. People react to alcohol in different ways, so no one can really say for sure how much alcohol (if any) is safe.

Although the risk is higher with heavy alcohol use, any amount of alcohol may affect your unborn baby. You can prevent FASD by not drinking at all while you are pregnant. Many doctors suggest just that.

The effects that alcohol has on an unborn baby depend on:

• How much, how often, and at what stage of pregnancy the mother drinks alcohol. The worst effects often are related to heavy alcohol use (5 or more drinks on at least one occasion).
• Whether the mother used other drugs, smoked, or had poor health for any reason while she was pregnant. In these cases, the child is more likely to have problems.
• Traits passed down through families. Some babies are more likely to be harmed by alcohol than others. It’s not clear why, but there may be a genetic link.

What can you do if you're pregnant and have had alcohol?

Try to talk openly with your doctor if you have had alcohol while you're pregnant. The earlier you tell your doctor, the better the chances for your child.