Everything you need to know about the dangers of drinking alcohol during pregnancy.

pregnant woman drinking red wine
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Fetal alcohol syndrome (FAS) is an irreversible physical and mental condition that results from alcohol exposure to a fetus during pregnancy. "The behavioral and developmental abnormalities associated with fetal alcohol syndrome can cause a lifetime of difficulty for both the child and parents," says Eve Espey, M.D., an associate professor of obstetrics and gynecology at the University of New Mexico and a spokesperson for the American College of Obstetricians and Gynecologists (ACOG).

In fact, drinking alcohol during pregnancy is the leading known cause of intellectual disabilities and birth defects in the United States, on par with autism and outpacing Down syndrome, cerebral palsy, cystic fibrosis, and spina bifida.

Here's what you need to know about fetal alcohol syndrome, and how you can keep your baby safe.

What is Fetal Alcohol Syndrome?

FAS is one of a range of conditions that falls under the umbrella term “fetal alcohol spectrum disorders” (FASD). Also included in this group are partial fetal alcohol disorder (PFAS), alcohol-related neurodevelopmental disorder (ARND), and alcohol-related birth defects (ARBD). An FAS diagnosis may indicate damage in three areas: growth deficiency, developmental disability or brain damage, and facial malformations. FAS and FASD affect about 40,000 newborns each year in the United States.

What Causes Fetal Alcohol Syndrome?

Drinking any kind of alcohol (beer, wine, hard liquor) during pregnancy can raise your risk for FAS or one of the other fetal alcohol spectrum disorders. When you're pregnant and you consume a drink, it quickly enters your bloodstream and reaches your unborn baby by crossing the placenta. Because a developing baby's liver isn't fully formed, the baby is unable to process alcohol and it ends up in his bloodstream at the same (or an even higher) concentration that it would be for an adult. The presence of alcohol in utero interferes with the delivery of oxygen and nutrition to an unborn baby's growing tissues and organs, including the brain.

The Effects of Fetal Alcohol Syndrome

The symptoms of FAS range from subtle to major mental and physical disabilities. Signs of FAS can include:

  • Distinctive facial features (small eyes, very thin upper lip, short upturned nose, smooth skin surface between nose and upper lip)
  • Joint, limb, and finger deformities
  • Slow physical growth before and after birth
  • Hearing and vision problems
  • Small brain and head circumference
  • Poor coordination
  • Delayed mental development
  • Learning disorders
  • Short attention span
  • Poor impulse control
  • Extreme nervousness
  • Anxiety
  • Heart defects

Most babies with FAS don't have all of these obvious physical issues, but rather slight behavioral and learning problems that are sometimes misdiagnosed as autism or attention deficit hyperactivity disorder (ADHD).

How to Prevent Fetal Alcohol Syndrome

The good news is that FAS is completely preventable. It's easy to avoid this condition in every case of pregnancy if you understand that no amount of alcohol is safe when you're expecting a child. Even a single glass of beer, wine, or a mixed drink passes from the mother to her unborn baby and can be potentially damaging. "Although it may seem benign to have a drink once in a while when you're pregnant, the stakes of doing so are very high – your baby's future health," Dr. Espey says.