Fetal alcohol syndrome, or FAS, is a collection of growth and brain development problems in newborns. When the mother drinks alcohol during pregnancy, her baby is at risk for FAS. Fetal alcohol effects, or FAE, is the term for a condition in which the baby has symptoms of FAS, but they are less severe. Alcohol-related neurodevelopmental disorder, or ARND, refers to children who exhibit only the behavioral and emotional problems of FAS. They don't show any developmental delay or growth problems.

What is going on in the body?

When a pregnant woman drinks alcohol, it passes easily through the placenta to her fetus. The developing baby gets a high concentration of alcohol. The fetus can't eliminate the alcohol as well as the mother can. Because of this, the fetus is subject to high alcohol levels for a longer time. No one knows exactly how much alcohol will cause FAE or FAS. Pregnant women vary in their ability to break down the alcohol. The mother's age, time of drinking, and food ingested with the alcohol all affect the amount passed to the baby.

Alcohol causes a broad range of defects. The severity of the disorder also can vary widely. Physical problems can range from many defects to none. Mental retardation can vary from severe disability to subtle learning problems. How the fetus is affected depends on when in the pregnancy alcohol use was heaviest. Use early in pregnancy is more likely to cause brain or body malformation. Use late in pregnancy is more likely to affect fetal nutrition and more subtle areas of brain function. These include personality and the ability to learn.

What are the causes and risks of the condition?

Not all women who abuse alcohol during pregnancy have children with FAS. However, the risks are clearly related to the amount of alcohol used during the pregnancy. FAS occurs in 30% to 50% of pregnancies in which the mother drinks heavily throughout the pregnancy. The impact of lesser amounts of alcohol on the fetus is not known.