This article is from the General Pregnancy FAQ, by swnymph@FensEnde.com (Sabrina Cuddy) with numerous contributions by others.
Fetal alcohol syndrome (FAS) is a distinct pattern of physical and
mental abnormalities that shows up in infants born to women who drank
during their pregnancies. Its symptoms include some or all of the
following: low birth weight, poor coordination, facial deformities,
heart defects, hyperactivity and mental retardation. The complete
syndrome occurs in roughly one or two out of every 1,000 births.
FAS ranks with Down syndrome and spina bifida as a major cause of
mental retardation. Because a fetus can't metabolize alcohol as
quickly as an adult can, alcohol remains in a unborn baby's system
longer than it does in the mother's. Doctors don't know how much
alcohol it takes to cause any of the FAS symptoms, so we recommend that
women abstain from alcohol throughout pregnancy. In addition, women
trying to conceive are advised to avoid drinking alcohol. Mothers who
breastfeed also should avoid alcohol, as a woman's body passes along
the same level of alcohol in her milk as she has in her own system.