Prenatal exposure to alcohol alone is not sufficient to warrant a diagnosis of FAS. A diagnosis of FAS should be considered if documentation points to the presence of:
1) All three dysmorphic facial features: A smooth philtrum (the groove between the nose and upper lip flattens with increased prenatal alcohol exposure), thin vermillion border (the upper lip thins with increased prenatal alcohol exposure) and small palpebral fissures (eye width decreases with increased prenatal alcohol exposure).
2) Prenatal or postnatal growth deficit in height or weight and head circumference.
3) Central Nervous System (CNS) abnormality. CNS abnormalities are classified as structural, neurologic, or functional. For instance, evidence indicates a small or diminished overall head circumference (i.e., <10th percentile). CNS neurologic problems can include seizures not attributable to a postnatal brain trauma or fever or other soft neurologic signs outside normal limits (e.g., coordination problems, visual motor difficulties, nystagmus, or difficulty with motor control). Very often there is a degree of depression of IQ and a developmental history consistent with either ADHD, ASD or both.
The diagnosis should be classified on the basis of available history as confirmed PAE or unknown prenatal alcohol exposure.
The majority of individuals exposed to alcohol prenatally do not display all of the physical abnormalities required for a diagnosis of FAS. However, despite the absence of physical abnormalities, they still exhibit significant neurodevelopmental impairments and thus meet criteria for pFAS or ARND. As a result, there is growing research interest in elucidating the neurodevelopmental impairments associated with FASD, as brain damage appears to be the most prevalent and devastating consequence of PAE.