Fetal alcohol syndrome (FAS) is a pattern of mental and physical defects that can develop in a fetus in association with high levels of alcohol consumption during pregnancy. Current research also implicates other lifestyle choices made by the prospective mother. Indications for lower levels of alcohol are inconclusive. The current recommendation of both the Surgeon General of the United States and the British Department of Health is to drink no alcohol at all during pregnancy.
Alcohol crosses the placental barrier and can stunt fetal growth or weight, create distinctive facial stigmata, damage neurons and brain structures, which can result in psychological or behavioral problems, and cause other physical damage. Surveys found that in the United States, 10–15% of pregnant women report having recently used alcohol, and up to 30% use alcohol at some point during pregnancy.
The main effect of FAS is permanent central nervous system damage, especially to the brain. Developing brain cells and structures can be malformed or have development interrupted by prenatal alcohol exposure; this can create an array of primary cognitive and functional disabilities (including poor memory, attention deficits, impulsive behavior, and poor cause-effect reasoning) as well as secondary disabilities (for example, predispositions to mental health problems and drug addiction). Alcohol exposure presents a risk of fetal brain damage at any point during a pregnancy, since brain development is ongoing throughout pregnancy.
Fetal alcohol exposure is the leading known cause of intellectual disability in the Western world. In the United States and Europe, the FAS prevalence rate is estimated to be between 0.2-1.5 in every 1000 live births. The lifetime medical and social costs of FAS are estimated to be as high as US$800,000 per child born with the disorder.