History and exam

Key diagnostic factors

common

gestation <37 weeks

Children are often preterm and are of low birth weight for gestational age. Intrauterine growth retardation may have been evident during pregnancy.

low height, weight, head circumference

These measurements should be plotted on growth charts for the relevant population. Height and weight measurements will be <10th percentile for age and head circumference <3rd percentile. Postnatal growth may also be <10th percentile.

characteristic facial dysmorphology

Children may have the following features: short palpebral fissure (<10th percentile for age), thin upper lip or vermillion border (rank 4 or 5 on lip-philtrum guide), and smooth philtrum (rank 4 or 5 on lip-philtrum guide). FAS Diagnostic and Prevention Network: lip-philtrum guides Opens in new window​​

The face should be examined for the following features: flat midface, large ears with "railroad-track" ear abnormality, epicanthic folds, hypertelorism (wide-spaced eyes), ptosis (droopiness of the eyelids), micrognathia (undersized jaw), microphthalmia (small eyes), and cleft lip and/or palate.

presence of birth defects

Cardiac anomalies include atrial septal defects, ventricular septal defects, aberrant great vessels, tetralogy of Fallot, and conotruncal defects.

Musculoskeletal anomalies include hypoplastic nails, shortened fifth fingers, radioulnar synostosis, flexion contractures, camptodactyly, clinodactyly of the fifth finger, pectus excavatum or carinatum, Klippel-Feil syndrome, hemivertebrae, scoliosis, and hockey-stick palmar creases.

Renal anomalies include aplastic, dysplastic, or hypoplastic kidneys, ureteral duplication, hydronephrosis, or horseshoe kidneys.

Ocular anomalies include strabismus, retinal vascular anomalies, or refractive problems.

developmental delay and behavioral problems

Infants may show developmental delay, including delayed motor milestones and/or delayed speech and language development.

Children may have problems with language, speech, learning, attention, or behavior.

Adolescents may exhibit poor educational performance or poor social skills, and have a history of drug/alcohol abuse or contact with the law/incarceration.

mental health problems

Adolescents may experience anxiety, depression, and/or personality disorders.

sibling with similar symptoms

A significant proportion of siblings are similarly affected.

Other diagnostic factors

common

hearing or vision impairment

Conductive and/or sensorineural hearing loss may be present.

Ocular anomalies include strabismus, retinal vascular anomalies, and refractive problems.

Formal age-appropriate audiologic and ophthalmologic assessments are required for all children with a suspected diagnosis.

poor feeding

Nonspecific symptom in infants.

irritability

Nonspecific symptom in infants.

Risk factors

strong

maternal alcohol intake during pregnancy

Alcohol is teratogenic and may cause a wide range of structural birth defects involving the central nervous system, face, and other organs.[11]

Women with an affected child are more likely to have consumed alcohol during all trimesters of pregnancy.[18] Mothers who drank 5 or more drinks in one session (i.e., binge drinking) are more likely to have a child with functionally significant developmental problems.[15]

Mothers should be questioned about their alcohol intake before and during pregnancy, at every prenatal visit, including quantity, timing, pattern of consumption, and frequency of binge drinking.

current maternal alcohol intake

Women with an affected child are more likely to be current drinkers, have a higher current alcohol intake, and have had one or more episodes of binge drinking (i.e., 5 or more drinks in one session) in the past week.[15]

higher parity/gravidity

Associated with increased risk of fetal alcohol syndrome (FAS) in children exposed to alcohol in utero.[15][18]

higher birth order of child

Associated with increased risk of FAS in children exposed to alcohol in utero.[15][18]

weak

maternal ADH1B*1/ADH1B*3 or ADH1B*1/ADH1B*1 genotype

Different alleles for the maternal alcohol dehydrogenase (an enzyme that catalyzes the rate-limiting step in alcohol metabolism) gene are thought to confer either protection or an increased risk of adverse fetal outcomes.

Women with the ADH1B*1/ADH1B*3 genotype who drink alcohol during pregnancy have an increased risk of having a child with FAS.[19]

Women with the ADH1B*1/ADH1B*1 genotype who drink alcohol during pregnancy have an increased risk of having a low birth-weight child, or a child with lower developmental quotient.[19]

The ADH1B genotype may influence maternal alcohol intake (increased or decreased).[19]

Some studies suggest that the ADH1B*2/ADH1B*3 genotype may be protective, but results are conflicting.[19]

longer history of maternal alcohol consumption

Associated with an increased risk of FAS in children exposed to alcohol in utero.[15][18]

increasing maternal age

Associated with an increased risk of FAS and neurodevelopmental problems,[18][20] although some studies dispute this.[21][15]

decreased maternal weight, height, and head circumference

Mothers of children with FAS have a significantly lower body mass index, weight, height, and head circumference. This may be associated with poor nutrition and risky alcohol use and in some cases may reflect maternal exposure to alcohol in utero.[21][15][18]

maternal tobacco use during pregnancy

Associated with an increased risk of FAS in children exposed to alcohol in utero.[21][15][18] Current tobacco use and smoking during all trimesters of pregnancy also increase risk.

low maternal socioeconomic status

Associated with an increased risk of FAS in children exposed to alcohol in utero.[21][15][18]

maternal family history of alcohol consumption

Associated with an increased risk of FAS in children exposed to alcohol in utero.[21][15][18]

maternal Indigenous ethnicity

Higher reported rates of FASD in indigenous communities may reflect the fact that indigenous women have multiple risk factors associated with low socioeconomic status and historic trauma and/or also the focus of research of FASD in these communities.

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