Fetal alcohol spectrum disorder

Fetal alcohol spectrum disorder refers to several conditions that arise from alcohol exposure before birth. Globally, about 7.7 out of every 1,000 people are affected, though the condition is often missed or incorrectly diagnosed. The forms, ranked from most to least severe, include fetal alcohol syndrome (FAS), partial fetal alcohol syndrome (pFAS), alcohol-related neurodevelopmental disorder (ARND), and neurobehavioral disorder associated with prenatal alcohol exposure (ND-PAE). Older terms like fetal alcohol effects, partial fetal alcohol effects, alcohol-related birth defects, and static encephalopathy are no longer used for this spectrum.

Not every infant exposed to alcohol during pregnancy develops FASD or complications. The likelihood rises with higher amounts, more frequent drinking, and longer duration of alcohol use—especially binge drinking. Why outcomes vary so much is not well understood. Diagnosis requires a team of professionals who assess growth, facial features, central nervous system function, and alcohol exposure. Key criteria for FASD are nervous system damage and alcohol exposure; FAS specifically includes growth deficiency and certain lip malformations. FASD is frequently mistaken for ADHD or occurs alongside it.

Experts widely advise that pregnant women avoid alcohol entirely to prevent FASD. Since a woman may not know she is pregnant for several weeks, abstinence is also recommended when trying to conceive. There is no cure, but treatment can help. Options include psychoactive medications, behavioral therapies, tailored support, and case management.

For a diagnosis of fetal alcohol syndrome, three main signs are required: growth deficiency or failure to thrive (such as low birth weight, small head size, or slow growth), specific lip malformations (short palpebral fissures, smooth philtrum, thin upper lip), and nervous system damage (structural, neurological, or functional impairment). Popova and colleagues identified 428 ICD-10 conditions that co-occur with FAS. Among those not used for diagnosis, conditions seen in at least half of individuals include conduct disorder, behavioral problems, impulsivity, developmental language disorder, hearing loss, visual impairment (including blindness or astigmatism), developmental delay, cognitive disorder, premature birth, substance dependence, congenital retinal malformation, fused cervical vertebrae, ADHD or impaired attention, and small or widely spaced eyes.

Other FASD conditions are partial forms of FAS, where the central nervous system shows deficits but without the growth or facial signs. This can lead to misdiagnosis as primary mental health disorders like ADHD or oppositional defiant disorder, even though brain damage is the root cause—requiring a different treatment approach. These conditions may not yet be official ICD or DSM diagnoses, but they still cause significant functional impairment. Many effects are developmental, so a child may appear normal at birth, but intellectual disabilities may only become clear once school begins.

Broader associations with alcohol use during pregnancy include intellectual disability (in IQ and functional tests), fetal death (miscarriage, stillbirth, sudden infant death syndrome), domestic violence, and harm to the infant. Babies may have sleep and sucking problems. Heart issues can include a murmur that often resolves by age one, ventricular or atrial septal defect, tetralogy of Fallot, coarctation of the aorta, or rhythm problems. Bone anomalies involve abnormal joint position or function, altered palmar creases, small distal phalanges, and small fifth fingernails. Kidney problems include horseshoe, aplastic, dysplastic, or hypoplastic kidneys. Eye issues include strabismus, optic nerve hypoplasia (which can cause light sensitivity, poor vision, or involuntary eye movements), and cleft lip with or without cleft palate—alcohol is a folic acid antagonist, and heavy drinking or binge drinking in the first trimester has been linked to orofacial clefts. Occasional problems include ptosis, microphthalmia, webbed neck, short neck, radioulnar synostosis, spina bifida, and hydrocephalus. Alcohol can also harm a woman’s fertility. Adverse effects may lead to malnutrition, seizures, vomiting, and dehydration in the mother. She may experience anxiety and depression, which can increase the risk of child abuse or neglect. When a pregnant mother withdraws from alcohol, the infant may show effects such as irritability, frequent crying, and restlessness.