Fetal Alcohol Syndrome: causes, features, prevention and care

Characteristics and diagnosis

Diagnosis of FAS relies on a combination of growth, facial, and central nervous system (CNS) findings together with confirmed prenatal alcohol exposure, though some diagnoses are made when exposure is highly suspected. Common diagnostic features include:

• Growth deficits before or after birth (low weight or height).
• Distinctive facial appearance: smooth philtrum (the groove between nose and upper lip), a thin upper lip, and small eye openings.
• Evidence of CNS impairment: developmental delay, intellectual disability, learning difficulties, behavioral problems, or abnormalities on brain imaging.

Causes and biological basis

Alcohol crosses the placenta and can interfere with fetal development at many stages. It can disrupt cell growth, neural migration, and synapse formation, and it may increase oxidative stress and cell death. Facial features are often linked to damage occurring early in pregnancy, while brain development can be affected throughout gestation. Scientific guidance generally advises that no amount of alcohol is known to be safe during pregnancy.

History and epidemiology

The modern clinical description of FAS was established in the early 1970s and helped link maternal alcohol use to a reproducible pattern of birth defects. Since then the concept expanded to FASD to reflect a spectrum of outcomes ranging from mild learning problems to the full syndrome. Prevalence varies by population and by patterns of alcohol use; FAS and related disorders remain important preventable causes of neurodevelopmental disability in many regions.

Prevention, management and prognosis

Prevention centers on abstaining from alcohol when planning a pregnancy and during pregnancy. Other measures include public health education, screening and support for prospective parents, and counseling. There is no cure for FAS; treatment focuses on early identification, developmental therapies, educational supports, behavioral interventions, medication for associated symptoms, and social services to improve long-term outcomes. Multidisciplinary care teams often include pediatricians, neurologists, psychologists, speech and occupational therapists, and social workers.

It is important to distinguish FAS from the broader symptoms-based range of FASD presentations; not everyone exposed to alcohol in utero will have the full syndrome. For more clinical guidance and resources for families, see specialist clinical materials and public health pages: alcohol guidance, pregnancy resources, and screening tools available from health services.