Fetal Alcohol Syndrome

Introduction

• Description: Fetal alcohol spectrum syndrome is characterized by malformations found in infants born to mothers who have consumed alcohol during pregnancy. Abnormalities include structural malformations (predominantly facial), growth restriction, and neurologic abnormalities, including mental retardation.

• Prevalence: Estimates vary from 6/10,000 births to 2/1000 births and globally as high as 23/1000 births. US rates are estimated to be 1%–5% of births. Intrauterine exposure to alcohol is a leading cause of preventable birth defects and developmental disabilities.

• Predominant Age: Reproductive age for mothers, infants diagnosed at birth.

• Genetics: No genetic pattern.

Etiology and Pathogenesis

• Causes: Alcohol consumption during pregnancy (generally >3 oz/day). There does not appear to be a lower limit of safety, nor are the effects confined to one part of pregnancy. The severity of the effects appears to be proportional to the amount and duration of exposure. Clinically identifiable effects are generally not seen with sporadic exposures of less than 1 oz of alcohol per day, although absolute safety cannot be assured even at this dose, because alcohol is eliminated from the fetal compartment at a rate of less than 5% of the maternal rate.

• Risk Factors: Alcohol use during pregnancy; other factors associated with alcohol use or abuse.

Signs and Symptoms

• Facial deformities (60%)—microcephaly, short palpebral fissures, flat midface, underdeveloped philtrum and thinned upper lip, low nasal bridge, epicanthal folds, minor ear anomalies, small teeth with faulty enamel, foreshortened nose and micrognathia may also be seen; two or more abnormal facial features must be present to make the diagnosis

• Cardiac malformations

• Deformities of joints, limbs, and fingers (eg, 5th finger clinodactyly, camptodactyly)

• Vision difficulties, including nearsightedness (myopia)

• Intrauterine and extrauterine growth restriction

• Mental retardation and developmental abnormalities, brain and spinal defects

• Abnormal behavior such as short attention span, hyperactivity, poor impulse control, extreme nervousness, and anxiety

Diagnostic Approach