Fetal Alcohol Syndrome - Diagnosis

Diagnosis

Several diagnostic systems have been developed in North America:

• The Institute of Medicine's guidelines for FAS, the first system to standardize diagnoses of individuals with prenatal alcohol exposure,
• The University of Washington's "The 4-Digit Diagnostic Code," which ranks the four key features of FASD on a Likert scale of one to four and yields 256 descriptive codes that can be categorized into 22 distinct clinical categories, ranging from FAS to no findings.
• The Centers for Disease Control's "Fetal Alcohol Syndrome: Guidelines for Referral and Diagnosis," which established general consensus on the diagnosis FAS in the U.S. but deferred addressing other FASD conditions, and
• Canadian guidelines for FASD diagnosis, which established criteria for diagnosing FASD in Canada and harmonized most differences between the IOM and University of Washington's systems.

Fetal alcohol syndrome is the only expression of FASD that has garnered consensus among experts to become an official ICD-9 and ICD-10 diagnosis. To make this diagnosis (or determine any FASD condition), a multi-disciplinary evaluation is necessary to assess each of the four key features for assessment. Generally, a trained physician will determine growth deficiency and FAS facial features. While a qualified physician may also assess central nervous system structural abnormalities and/or neurological problems, usually central nervous system damage is determined through psychological assessment. A pediatric neuropsychologist may assess all areas of functioning, including intellectual, language processing, and sensorimotor. Prenatal alcohol exposure risk may be assessed by a qualified physician or psychologist.

The following criteria must be fully met for an FAS diagnosis:

1. Growth deficiency — Prenatal or postnatal height or weight (or both) at or below the 10th percentile
2. FAS facial features — All three FAS facial features present
3. Central nervous system damage — Clinically significant structural, neurological, or functional impairment
4. Prenatal alcohol exposure — Confirmed or Unknown prenatal alcohol exposure

Alcohol intake is determined by interview of the biological mother or other family members knowledgeable of the mother's alcohol use during the pregnancy, prenatal health records, and review of available birth records, court records, chemical dependency treatment records, or other reliable sources. Exposure level is assessed as Confirmed Exposure, Unknown Exposure, and Confirmed Absence of Exposure by the IOM, CDC and Canadian diagnostic systems. The "4-Digit Diagnostic Code" further distinguishes confirmed exposure as High Risk and Some Risk:

• 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, which rules out an FAS diagnosis.