Introduction
Fetal alcohol syndrome, or FAS, occurs because of maternal use of alcohol during pregnancy.
Spectrum of conditions that can occur in a person whose mother drank alcohol during pregnancy.
- M/C cause of intellectual disability in US
Foetal alcohol spectrum disorders (FASDs):
- Fetal alcohol syndrome (FAS)
- Partial fetal alcohol syndrome (pFAS)
- Alcohol-related neurodevelopmental disorder (ARND)
- Alcohol-related birth defects (ARBD)
Clinical features
Growth deficiency
4-Digit Diagnostic Code:
- Severe: Height and weight at or below the 3rd percentile.
- Moderate: Either height or weight at or below the 3rd percentile, but not both.
- Mild: Either height or weight or both between the 3rd and 10th percentiles.
- None: Height and weight both above the 10th percentile.
Three FAS facial features:
- Smooth philtrum: The divot or groove between the nose and upper lip flattens with increased prenatal alcohol exposure
- Thin vermilion: The upper lip thins with increased prenatal alcohol exposure
- Small palpebral fissures: Eye width decreases with increased prenatal alcohol exposure
CNS damage
4-Digit Diagnostic Code:
- Definite: Structural/neurological impairments for FAS/static encephalopathy.
- Probable: Significant dysfunction of 2 SD or worse in ≥ 3 functional domains.
- Possible: Mild-moderate dysfunction of 2 SD or worse in 1 or 2 functional domains or by judgment of the clinical evaluation team that CNS damage cannot be dismissed.
- Unlikely: No evidence of CNS damage.
Diagnosis
Fetal alcohol syndrome (FAS) diagnostic criteria
- Growth deficiency: Prenatal/postnatal height/weight (or both) ≤ 10th percentile
- FAS facial features: All 3 FAS facial features present
- CNS damage: Clinically significant structural neurological, or functional impairment
- Prenatal alcohol exposure: Confirmed/unknown prenatal alcohol exposure
Partial fetal alcohol syndrome (pFAS) diagnostic criteria
- Growth deficiency: Growth/height range from normal to deficient
- FAS facial features: 2-3 FAS facial features present
- CNS damage: Clinically significant structural, neurological, or functional impairment in ≥ 3 of the Ten Brain Domains
- Prenatal alcohol exposure: Confirmed prenatal alcohol exposure
Alcohol-related neurodevelopmental disorder (ARND) or static encephalopathy diagnostic criteria:
- Growth deficiency: Growth/height range from normal to minimally deficient
- FAS facial features: Minimal or no FAS facial features present
- CNS damage: Clinically significant structural, neurological, or functional impairment in ≥ 3 of the Ten Brain Domains
- Prenatal alcohol exposure: Confirmed prenatal alcohol exposure
Clinical diagnosis
Ten Brain Domains:
- Achievement, adaptive behavior, attention, cognition, executive functioning, language, memory, motor skills, multisensory integration or soft neurological problems, social communication
Exposure confirmation “4-Digit Diagnostic Code”
- High risk: Confirmed use of alcohol during pregnancy known to be at high blood alcohol levels (100 mg/dL or greater) delivered at least weekly in early pregnancy.
- Some risk: Confirmed use of alcohol during pregnancy with use less than High Risk or unknown usage patterns.
- Unknown risk: Unknown use of alcohol during pregnancy.
- No risk: Confirmed absence of prenatal alcohol exposure.
Differential diagnosis:
9 syndromes that have overlapping features with FAS (CDC. However, none of these syndromes include all three FAS facial features, and none are the result of prenatal alcohol exposure:
- Aarskog syndrome
- Williams syndrome
- Noonan syndrome
- Dubowitz syndrome
- Brachman-DeLange syndrome
- Toluene syndrome
- Fetal hydantoin syndrome
- Fetal valproate syndrome
- Maternal PKU fetal effects