From the Research
The sentinel facial features of Fetal Alcohol Spectrum Disorder (FASD) include three specific characteristics: short palpebral fissures, a smooth or flattened philtrum, and a thin upper lip vermilion. These features are necessary for the diagnosis of Fetal Alcohol Syndrome (FAS) and partial FAS, and are specific for prenatal alcohol exposure 1. The physical features of FASD can be explained by the damage to the brain during pregnancy and can be replicated in animal models 1. The diagnosis of FASD should be based on universal clinical criteria, which include the assessment of growth deficits, microcephaly, and the three facial features (short palpebral fissures, smooth philtrum, and narrow vermillion of the upper lip) 1. Other dysmorphic features, particularly in the hands, are also key to the recognition of FAS 1. The presence of these facial features is highly specific for prenatal alcohol exposure, though they appear in only a minority of individuals with FASD 2. The facial features are most distinct during early childhood (between ages 2-11) and may become less apparent during adolescence and adulthood 3. Standardized measurement techniques, such as the University of Washington Lip-Philtrum Guide, should be used to assess the philtrum and upper lip, with scores of 4 or 5 indicating abnormality 3. For palpebral fissure length, measurements below the 10th percentile for age and race are considered significant 3. Not all individuals with FASD will display these facial features, as their presence depends on timing, dose, and pattern of alcohol exposure during pregnancy 4. The facial features reflect alcohol's disruptive effect on facial development during a specific window of embryonic development (days 19-21 after conception), which coincides with the formation of midline facial structures and parts of the central nervous system 5. Some key points to consider when assessing facial features in FASD include:
- The use of standardized measurement techniques to assess the philtrum and upper lip
- The evaluation of palpebral fissure length and comparison to age and race norms
- The consideration of other dysmorphic features, particularly in the hands
- The recognition that the presence of facial features depends on timing, dose, and pattern of alcohol exposure during pregnancy
- The importance of universal clinical criteria for the diagnosis of FASD.