Fetal alcohol syndrome is a neonatal condition caused by exposure to excessive ethanol in utero, resulting in neurodevelopmental abnormalities and growth retardation. Patients with fetal alcohol syndrome can have variable phenotypes. Typical characteristics include facial dysmorphology (eye, ear, teeth), cardiac defects, microcephaly, intellectual disability, and limited joint mobility. Other features include low birth weight and behavioral and cognitive deficits. Infants and children may present with failure to thrive, irritability, nystagmus, hypotonia, sleep disturbance, and seizures. Jaundice, icteric sclera, joint contractures, corneal opacities, and blurred vision may also be present.

Fetal alcohol syndrome does not progress, although the deficits of cognition and the dysmorphic features due to altered embryologic development are irreversible.