A 2-month-old infant being evaluated for congenital hypothyroidism would have which finding as a consistent sign?

• A. The infant sleeps for 2 hours
• B. The infant is tachypneic
• C. The infant has frequent vomiting
• D. The infant sleeps for 6 hours at a time

Answer: (D)

Congenital hypothyroidism slows overall metabolism and reduces alertness in infants, so they often appear lethargic with decreased activity and longer periods of sleep between feeds. An infant who sleeps for six hours at a time fits this pattern of reduced wakefulness and responsiveness, which is a common early sign. Tachypnea would indicate respiratory or metabolic distress rather than a primary hypothyroid presentation. Frequent vomiting isn’t typical for congenital hypothyroidism, and while many healthy infants have irregular sleep, the marked increased sleepiness aligns more with hypothyroid effects on energy and activity.