Fetal alcohol syndrome (FAS)

Synonyms: FAS, Alcohol-related birth defects, Fetal alcohol effects

Medical Specialties: Family practice, Obstetrics/gynecology, Pediatrics

Clinical Definition

Fetal alcohol syndrome, or FAS, is a collection of congenital defects, such as ventricular septal defect or atrial septal defect, facial abnormalities and other developmental problems caused by exposure of the fetus to alcohol during pregnancy. Alcohol consumption during the first trimester is most hazardous.

In Our Own Words

Fetal alcohol syndrome, or FAS, is a collection of birth defects due to a woman consuming alcohol during pregnancy. The alcohol easily passes across the placenta to the fetus and can harm the baby's development.


A baby with FAS may have decreased muscle tone, poor coordination, delayed development and growth, heart defects and facial abnormalities. No safe level of alcohol during pregnancy has been set, and drinking during the first three months or trimester is considered the most harmful. While the outcome for affected babies varies, normal brain development is not common.

Relevant Conditions
  • Developmental delay
  • Congenital heart defects
Side Effects
  • Delay in development
  • Heart problems
  • Facial abnormalities such as a small head
  • Poor muscle tone and/or coordination
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