Fetal Alcohol Spectrum Disorder

Fetal alcohol spectrum disorder (FASD) is a lifelong group of neurodevelopmental and physical conditions caused by prenatal alcohol exposure. Global prevalence is about 7.7 per 1,000 population, with estimates of 2 to 5% of schoolchildren in some Western countries and above 10% in some high risk populations. Alcohol is a teratogen in any trimester, and no safe level has been established.

Mechanisms include oxidative stress, apoptosis of neural crest cells and neurons, impaired cell adhesion and migration, epigenetic disruption and placental vasoconstriction. Risk is modified by the pattern of drinking (binge drinking), maternal alcohol metabolism genetics, malnutrition, smoking, age and polymorphisms.

Diagnostic categories: fetal alcohol syndrome (FAS), partial FAS, alcohol related neurodevelopmental disorder (neurobehavioural disorder associated with prenatal alcohol exposure) and alcohol related birth defects.

• Facial features: short palpebral fissures (at or below the 3rd centile), smooth philtrum (rank 4 or 5 on the lip philtrum guide), thin upper lip vermilion (rank 4 or 5)
• Growth: prenatal or postnatal height or weight at or below the 10th centile
• Central nervous system: microcephaly (head circumference at or below the 10th centile), structural brain abnormalities (corpus callosum agenesis or hypoplasia, cerebellar hypoplasia, reduced basal ganglia volume), seizures, and impairment in at least three domains: cognition, language, memory, attention, executive function, motor skills, social communication, adaptive behaviour
• Behaviour and mental health: ADHD, impulsivity, poor judgement, learning difficulty (especially mathematics), emotional dysregulation, anxiety, depression, sleep problems, and secondary disabilities (school failure, substance use, trouble with the law, homelessness, victimisation)
• Associated defects: congenital heart defects (ASD, VSD), renal anomalies, skeletal anomalies (radioulnar synostosis, scoliosis, camptodactyly), strabismus, ptosis, optic nerve hypoplasia, refractive errors, sensorineural or conductive hearing loss

• Diagnosis is clinical and needs multidisciplinary assessment (paediatrician or geneticist, psychologist, speech therapist, occupational therapist). Components:
  1. Confirmed or highly probable prenatal alcohol exposure (maternal report, collateral history, medical or social records, biomarkers such as meconium fatty acid ethyl esters or phosphatidylethanol in newborn dried blood spots). Confirmed exposure is not essential for FAS when the sentinel facial features are present
  2. Facial measurement with standardised lip philtrum guides and palpebral fissure length charts
  3. Growth and head circumference
  4. Neurodevelopmental and cognitive testing, with scores 2 or more standard deviations below the mean in three or more domains
  5. Exclusion of other causes: chromosomal microarray, fragile X testing where indicated, and other syndromes with overlapping features (Williams, Noonan, DiGeorge, Cornelia de Lange, Dubowitz, Aarskog), with brain MRI when indicated
  6. Screening for comorbidity: echocardiography, renal ultrasound, hearing, vision and spine

There is no cure. Early diagnosis, a stable supportive environment and early intervention improve outcomes.

• Multidisciplinary care with a case coordinator: individualised education plan, structured routines, visual aids, clear concrete instructions, reduced sensory overload, speech and language therapy, occupational therapy, physiotherapy and social skills training
• Behaviour and mental health: parent and caregiver training, cognitive behavioural therapy adapted for executive function deficits. ADHD: methylphenidate 0.3 to 1 mg/kg/day starting low (about 50% respond), or guanfacine or clonidine. SSRIs for anxiety and depression. Melatonin 1 to 5 mg for sleep. Risperidone or aripiprazole only for severe aggression
• Medical: surgery for cardiac and renal defects, correction of visual and hearing impairment, antiepileptic drugs for seizures, and monitoring of growth and nutrition
• Psychosocial: stable housing, foster or adoptive placement when needed, support for foster and adoptive parents, transition planning in adolescence (supported living, vocational training, guardianship decisions), and prevention of secondary disabilities
• Maternal care: non-judgemental support and treatment of alcohol use disorder (brief intervention; naltrexone 50 mg daily or acamprosate 666 mg three times daily; psychosocial treatment), contraception counselling for women at risk, and screening with AUDIT-C or T-ACE in pregnancy and preconception care
• Prevention: abstinence from alcohol in pregnancy and when planning pregnancy; screening in antenatal and primary care. Recurrence in later pregnancies is high if drinking continues