AssessmentsFetal alcohol syndrome
Fetal alcohol syndrome
USMLE® Step 1 style questions USMLE
USMLE® Step 2 style questions USMLE
A 1-day-old male infant is brought to the newborn nursery two hours after birth. He was born via vaginal delivery at 38 weeks gestation. The infant’s mother did not receive prenatal care. Family history is unremarkable for hereditary disorders. Weight and length are at the 5th percentile. Vitals are within normal limits. Physical examination reveals microcephaly, short palpebral fissures, a thin vermillion border, and a smooth philtrum. A harsh holosystolic murmur is heard at the lower left sternal border on cardiac auscultation. This infant’s physical exam findings are most likely secondary to in-utero exposure to which of the following?
Content Reviewers:Viviana Popa, MD
It’s currently the leading cause of intellectual disability in the US and can cause characteristic physical abnormalities.
Normally, the fetus is connected to the placenta by the umbilical cord, so the fetus gets oxygen and nutrients from the mother.
Unfortunately, ethanol and toxic alcohol metabolites like acetaldehyde also pass freely through the placenta, but the fetal liver doesn’t have the necessary enzymes to metabolize them, so they build up inside the fetus really fast.
In FAS, ethanol interferes with cell division and proliferation, cell growth and differentiation, and with the migration of mature cells to their final location in the developing embryo, which affects the development of various fetal tissues, including the brain.
Alcohol-induced brain damage includes partial or complete agenesis of the corpus callosum, which links the two hemispheres together, so it either forms incompletely, or not at all.
This causes intellectual disability and seizures.
The most common symptom of FAS is growth retardation, resulting in low height and weight.
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