DHSS 


Diagnosing FAS

Individuals with FAS are a subset of individuals who are affected by in-utero exposure to alcohol. They are not necessarily the most severely affected individuals; they are simply the subset that can be positively identified because of their characteristic facial appearance (Clarren, S.K., & Astley, S.J. 1993). Other terms are often used to classify individuals who do not have FAS but share characteristics associated with FAS (especially central nervous system dysfunction and other cognitive abnormalities). These terms include fetal alcohol effects (FAE), static encephalopathy, neurobehavioral disorder, alcohol-related birth defects (ARBD), and alcohol-related neurodevelopmental disorder (ARND). These terms are sometimes used interchangeably. A diagnosis of alcohol-related effects may also be made with or without confirmed maternal alcohol exposure.

Fetal alcohol syndrome is a medical diagnosis usually made by a physician specifically trained in the assessment of birth defects. Other professionals often assist in identifying children with known maternal drinking histories or suspected problems. For example, nurses may be trained to recognize the facial features of children with fetal alcohol syndrome. It is important that the physician making the diagnosis is sensitive to the physical characteristics of the racial group with whom he or she is working because the physical characteristics of FAS may look slightly different among different racial groups.

Accurate diagnosis of alcohol-related effects require that the physician be qualified. Accurate identification can improve the child's opportunity to receive appropriate interventions, facilitate communication among clinicians, caregivers, and educators, and provides better self-awareness and understanding by family members.

 

The following information has been extracted from Ninth Special Report to the U.S. Congress on Alcohol and Health, June 1997(RP0973). Free copies of this report are available from National Clearinghouse for Alcohol and Drug Information, 1-800-729-6686.

A key concern in research and clinical practice continues to be how best to characterize and identify FAS and other ARBD arising from prenatal alcohol exposure. Research has shown that in utero alcohol exposure can produce a spectrum of harmful effects, ranging from a characteristic pattern of gross morphological anomalies and mental impairment (including mental retardation) to subtler cognitive and behavioral dysfunction. FAS is the most severe birth defect produced by in utero alcohol exposure. The terms "fetal alcohol effects" (FAE) and "alcohol-related birth defects" are used to describe individuals who exhibit only some of the attributes of FAS and thus do not fulfill the diagnostic criteria for the syndrome (Clarren and Smith 1978; Sokol and Clarren 1989). A medical diagnosis of FAS is differentiated from a "case definition" for surveillance purposes.

TABLE 1: Diagnostic Criteria for Fetal Alcohol Syndrome (FAS) and Alcohol-Related Effects

Fetal Alcohol Syndrome

1. FAS with confirmed maternal alcohol exposures

A. Confirmed maternal alcohol exposures

B. Evidence of a characteristic pattern of facial anomalies that includes features such as

short palpebral fissures and abnormalities in the premaxillary zone (e.g., flat upper lip, flattened philtrum, and flat midface)

C. Evidence of growth retardation, as in at least one of the following:

- low birth weight for gestational age

- decelerating weight over time not due to nutrition

- disproportional low weight to height

D. Evidence of CNS neurodevelopmental abnormalities, as in at least one of the following: - decreased cranial size at birth

- structural brain abnormalities (e.g., microcephaly, partial or complete agenesis of the corpus callosum, cerebellar hypoplasia)

- neurological hard or soft signs (as age appropriate), such as impaired fine motor skills, neurosensory hearing loss, poor tandem gait, poor eye-hand coordination

2. FAS without confirmed maternal alcohol exposure

B, C, and D as above

3. Partial FAS with confirmed maternal alcohol exposure

A. Confirmed maternal alcohol exposure'

B. Evidence of some components of the pattern of characteristic facial anomalies

Either C or D or E

C. Evidence of growth retardation, as in at least one of the following:

- low birth weight for gestational age

- decelerating weight over time not due to nutrition

- disproportional low weight to height

D. Evidence of CNS neurodevelopmental abnormalities, as in:

- decreased cranial size at birth

- structural brain abnormalities (e.g., microcephaly, partial or complete agenesis of the corpus callosum, cerebellar hypoplasia)

  • neurological hard or soft signs (as age appropriate) such as impaired fine motor skills, neurosensory hearing loss, poor tandem gait, poor eye-hand coordination

E. Evidence of a complex pattern of behavior or cognitive abnormalities that are inconsistent with developmental level and cannot be explained by familial background or environment alone, such as learning difficulties; deficits in school performance; poor impulse control; problems in social perception; deficits in higher level receptive and expressive language; poor capacity for abstraction or metacognition; specific deficits in mathematical skills; or problems in memory, attention, or judgment

TABLE 1 (continued)

Alcohol-Related Effects

Clinical conditions in which there is a history of maternal alcohol exposure,a,b and where clinical or animal research has linked maternal alcohol ingestion to an observed outcome. There are two categories, which may co-occur. If both diagnoses are present, then both diagnoses should be rendered:

4. Alcohol-related birth defects (ARBD)

List of congenital anomalies, including malformations and dysplasias

Cardiac Atrial septal defects Aberrant great vessels

Ventricular septal defects Tetralogy of Fallot

Skeletal Hypoplastic nails Clinodactyly

Shortened fifth digits Pectus excavatum and carinatum

Radiouinar synostosis Klippel-Feil syndrome

Flexion contractures Hemivertebrae

Camptodactyly Scoliosis

Renal Aplastic, dysplastic, Ureteral duplications

hypoplastic kidneys Hydronephrosis

Horseshoe kidneys

Ocular Strabismus Refractive problems 2ndary to small

Retinal vascular anomalies globes

Auditory Conductive hearing loss Neurosensory hearing loss

Other Virtually every malformation has been described in some patient with

FAS. The etiologic specificity of most of these anomalies to alcohol teratogenesis remains uncertain.

5. Alcohol-related neurodevelopmental disorder (ARND)

Presence of:

A. Evidence of CNS neurodevelopmental abnormalities, as in any one of the following:

- decreased cranial size at birth

- structural brain abnormalities (e.g., microcephaly, partial or complete agenesis of the

corpus callosum, cerebellar hypoplasia)

-neurological hard or soft signs (as age appropriate), such as impaired fine motor skills, neurosensory hearing loss, poor tandem gait, poor eye-hand coordination

and/or:

B. Evidence of a complex pattern of behavior or cognitive abnormalities that are inconsistent with developmental level and cannot be explained by familial background or environment alone, such as learning difficulties; deficits in school performance; poor impulse control; problems in social perception; deficits in higher level receptive and expressive language; poor capacity for abstraction or metacognition; specific deficits in mathematical skills; or problems in memory, attention, or judgment.

Copied with permission from: Institute of Medicine. Fetal Alcohol Syndrome: Diagnosis, Epidemiology, Prevention, and Treatment. Washington, DC: National Academy Press, 1996.

 

 

Diagnostic Criteria

The diagnostic criteria for FAS, which were initially standardized by the Fetal Alcohol Group of the Research Society on Alcoholism (Rosett 1980) and later modified by Sokol and Clarren (1989), are the following:

1. Prenatal or postnatal growth deficiency or either (weight, length, or both below the 10th percentile when corrected for gestational age).

2. Central nervous system (CNS) disorders, including neurological abnormality, developmental delay, intellectual impairment, and structural abnormalities.

3. A distinctive pattern of facial anomalies, including short palpebral fissures (eye openings); a thin upper lip; an elongated, flattened midface; and an indistinct philtrum (the zone between the nose and the mouth).

Maternal alcohol use during pregnancy should be documented to confirm a FAS diagnosis (Aase 1994).

Despite consensus regarding these criteria, researchers and clinicians continue to experience considerable difficulty in diagnosing FAS, in large part because none of the characteristic abnormalities is specific to the diagnosis (Aase 1994). A person who is otherwise healthy may display one or two of the diagnostic traits.

Furthermore, specific facial abnormalities can be subtle and difficult to recognize; their expression can change as a person ages (Aase 1994; Streissguth et al. 1991); and their severity may vary among individuals as well as among different racial and ethnic groups (Abel and Sokol 1991; Ernhart et al. 1989; May 1991; Sokol et al. 1986).

 

Difficulties in Diagnosis

Clinicians face a particular dilemma in identifying and intervening with children and adults who exhibit only some of the characteristic attributes of FAS. Even though these individuals do not fulfill the diagnostic criteria for FAS, they often have behavioral (Nanson and Hiscock 1990; Streissguth et al. 1989a,b) and cognitive (Streissguth et al. 1991) problems that persist with age and can restrict normal functioning. 'Possible fetal alcohol effects" (Clarren and Smith 1978) and "alcohol-related birth defects" (Sokol and Clarren 1989) have been suggested as descriptive terms to categorize the problems experienced by such individuals. When used appropriately in clinical practice, these terms indicate that prenatal alcohol exposure is suspected as the responsible cause for the observed abnormalities, but further proof is needed for confirmation. These terms, however, are not diagnoses. The individual abnormalities of FAS can develop from various genetic or environmental influences (Aase 1994), and it is nearly impossible to prove that the problems in any one child are the result of prenatal alcohol exposure. A recent study by the Institute of Medicine (IOM; 1996) proposed five modified diagnostic categories and criteria in an effort to resolve issues that seem to be confusing to the clinical and research communities:
  1. FAS with confirmed maternal alcohol exposure,
  2. FAS without confirmed maternal alcohol exposure,
  3. partial FAS with confirmed maternal alcohol exposure,
  4. alcohol-related birth defect (ARBD),
  5. alcohol-related neurodevelopmental disorder (ARND).

Because the manifestations of FAS, ARBD, and ARND may vary in specific individuals, the study recommends that clinicians should add to a diagnosis the descriptions of patients' distinctive problems. Such information can broaden our understanding of these disorders.

Diagnosis of FAS in a newborn can be particularly challenging for several reasons. Because CNS dysfunction, which is a hallmark of FAS, may not be detected until several years after birth, a clinician often relies primarily on identifying the syndrome's characteristic facial features. These features, however, can be quite subtle and thus particularly difficult to recognize in the neonate. The fact that some of the distinguishing features (specifically, midfacial under-development) can occur normally in many newborns (Aase 1994) and that normal swelling around the eyes in newborn infants often obscures the characteristic anomalies further complicates diagnosis within this age group (Sokol and Clarren 1989). It is not surprising, then, that FAS is diagnosed readily at birth in only the most severely affected children and that many FAS cases go undetected at this time (Abel and Sokol 1987; Little et al. 1990; Sokol and Clarren 1989).

In older children and in adults, diagnosis also is difficult because some of the representative features become less distinctive with age. The onset of adolescence often brings a change to the characteristic slender build of children with FAS, particularly in girls (Streissguth et al. 1991). Facial appearance begins to normalize with age as continued slow growth of the face, chin, and nose through adolescence compensates for underdevelopment of the midface (Streissguth et al. 1991). Although certain characteristic features of FAS can be recognized in severely affected children even in adolescence, FAS becomes more difficult to diagnose in children with mild expression of the syndrome (Spohr et al. 1993). Because adult height and head circumference usually remain below normal, however, and abnormalities of the eyes and upper lip are seen in 80 percent of adolescents and adults with FAS, these features can be valuable for diagnosing older persons Streissguth et al. 1991).

Normal variations of particular facial features in certain racial groups (Abel and Sokol 1991; Ernhart et al. 1989; May 199 1; Sokol et al. 1986) and in particular families (Aase in press) also can influence diagnosis. For example, a moderate degree of midfacial underdevelopment is a normal feature in many Native American groups. Broader lips normally seen in African-American children may mask the thin upper lip that is seen in FAS, and the characteristic tall stature of some northern European and central African populations may obscure FAS-related growth deficiency (Aase 1994). Similarly, such family traits as IQ, height, facial features, and even creases on the palm (Streissguth et al. 1991) may be heavily influenced by heredity and can either mask or mimic the features of FAS (Aase 1994). These variations can complicate diagnostic efforts and should be considered in the diagnostic process.

Given the challenges that face diagnosticians, Abel et al. (1993) designed a study to determine whether medical providers (obstetricians and pediatricians) and biomedical researchers not formally trained in dysmorphology could accurately and consistently identify in facial photographs those infants who had and did not have FAS. Study participants in both groups generally were able to accurately identify FAS on the basis of photographs alone. Moreover, identification of FAS was highly correlated with maternal drinking behavior, thus underscoring that facial features and maternal drinking are associated. With the provision of additional information to the participants, such as birth weight, the accuracy of identification increased only among biomedical scientists. This finding suggests that the clinicians were less influenced in their evaluations by supplementary diagnostic information. The race of the photographed children, however, influenced the accuracy of identification ratings within occupational groups. African American children were more likely than Caucasian children to be incorrectly classified as having FAS. Because all but one of the study participants were Caucasian, this bias implies that lack of knowledge of normal African-American features can influence the accuracy of diagnosis. The authors noted that the findings should be considered in light of a potential shortcoming of the study. Only photographs of children with FAS and healthy children were used. Thus, the study confirms that the participants could distinguish between normal and unusual-looking children but not necessarily between children with FAS and children with other birth defects (Abel et al. 1993).

To date, FAS is more commonly identified by an overall pattern of facial features than by specific individual facial characteristics (Astley et al. 1992; Clarren et al. 1987; Rostand et al. 1990). However, clinicians most frequently use the occurrence of small eye openings, smooth and long philtrum, thin upper vermilion (i.e., narrow red margin of the upper lip), increased inner canthal distance, and an elongated midface to diagnose FAS in infants and older children. An approach that employs a weighted checklist of distinguishing characteristics for FAS (Aase 1994; Smith et al. 1990; Sokol et al. 1986; Vitez et al. 1984) has proved to be of value in research and in "clinical screening" (increasing the number of appropriate referrals to diagnostic clinics), but it appears to be less effective as a diagnostic tool for clinical purposes (Aase 1994).

References:

Aase, J.M. Clinical recognition of FAS: Difficulties of detection and diagnosis. Alcohol Health Res World 18(1): 5-9, 1994.

Abel, E.L.; Martier, S.; Kruger, M.; Ager, J.; and Sokol, R. J. Ratings of fetal alcohol syndrome facial features by medical providers and biomedical scientists. Alcohol Clin Exp Res 17(3):717-721, 1993.

Abel, E.L., and Sokol, R.J. Incidence of fetal alcohol syndrome and economic impact of FAS-related anomalies. Drug Alcohol Depend 19(1):51-70, 1987.

Abel, E.L., and Sokol, R.J. A revised conservative estimate of the incidence of FAS and its economic impact. Alcohol Clin Exp Res 15(3):514, 1991.

Clarren, S.K., and Astley, S.J. A Screening Guide for Fetal Alcohol Syndrome. University of Washington, 1993.

Clarren, S.K.; Sampson, P.D., Larsen, J.; Donnell, D.J.; Barr, H.M.; Bookstein, F.L.; Martin, D.C.; and Streissguth, A.P. Facial effects of fetal alcohol exposure: Assessment by photographs and morphometric analysis. Am J Med Genet 26(3):651-666, 1987.

Clarren, S.K., and Smith, D.W. The fetal alcohol syndrome. N Engl J Med 298(19):1063-1067, 1978.

Ernhart, C.B.; Sokol, R.J.; Ager, J.W.; Morrow-Tlucak, M.; and Martier, S. Alcohol-related birth defects; Assessing the risk. Ann NY Acad Sci 562:159-172, 1989.

Institute of Medicine. Fetal Alcohol Syndrome: Diagnosis, Epidemiology, Prevention, and Treatment. Washington, DC: National Academy Press. 1996.

May. P.A. Fetal alcohol effects among North American Indians: Evidence and implications for society. Alcohol Health Res World 15(3):239-248, 1991.

 

Nanson, J.L., and Hiscock, M. Attention deficits in children exposed to alcohol prenatally. Alcohol Clin Exp Res 14(5):656-661, 1990.

Rosett, H.L. A clinical perspective of the fetal alcohol syndrome. Alcohol Clin Exp Res 4:119-122, 1980.

Rostand, A.; Kaminski, M.; Lelong, N.; Dehaene, P.; Delestret, I.: Klein-Bertrand, C.; Querleu, D.; and Crepin, G. Alcohol use in pregnancy, craniofacial features, and fetal growth. J Epidemiol Commun Health 44(4):302-306, 1990.

Smith, I.E.; Coles, C.D.; Fernhoff, P.M.; Sloan, K.; Pollard, J.; and Falek, A. Reliability and validity of dysmorphia assessment in children prenatally exposed to alcohol. Alcohol Clin Exp Res 14(2):340, 1990.

Sokol, R.J.; Ager, J.; Martier, S.; Debanne, S.; Ernhart, C.; Kuzma, J.; and Miller, S.I. Significant determinants of susceptibility to alcohol teratogenicity. Ann NY Acad Sci 477:87-102, 1986.

Sokol, R.J., and Clarren, S.K. Guidelines for use of terminology describing the impact of prenatal alcohol on the offspring. Alcohol Clin Exp Res 13(4):597.598, 1989.

Spohr, H.L.; Willms, J.; and Steinhausen, H.C. Prenatal alcohol exposure and long-term developmental consequences. Lancet 341(8850):907, 1993.

Streissguth, A.P.; Aase, J.M.; Claren, S.K.; Randels, S.P.; LaDue, R.A.; and Smith, D.F. Fetal alcohol syndrome in adolescents and adults. JAMA 265(15):1961-1965, 1991.

Streissguth, A.P.; Bookstein, F.L.; Sampson, P.D.; and Barr, H.M. Neurobehavioral effects of prenatal alcohol: Part III. PLS analyses of neuropsychologic tests. Neurotoxicol Teratol 11(5):493-507, 1989a.

Streissguth, A.P.; Sampson, P.D.; and Barr, H.M. Neurobehavioral dose-response effects of prenatal alcohol exposure in humans from infancy to adulthood. Ann NY Acad Sci 562:145-158, 1989b.

Vitez, M.; Koranyi, G.; Gonczy, E.; Rudas, T.; and Czeizel, A. A semiquantitative score system for epidemiologic studies of fetal alcohol syndrome. Am J Epidemiol 119(3):301-308, 1984.