In an infant being evaluated for congenital hypothyroidism, which of the following would be a concerning sign?

• A. The infant sleeps for 2 hours
• B. The infant sleeps for 6 hours at a time
• C. The infant feeds poorly but gains weight
• D. The infant has rapid breathing

Answer: (D)

Rapid breathing in a newborn points to respiratory distress or another acute issue, which requires urgent evaluation. Congenital hypothyroidism tends to present with slowed activity and feeding difficulties rather than problems with breathing. Babies may be lethargic or sleep excessively and have poor feeds, but they don’t typically show rapid, labored respiration as an early sign. So this finding stands out as a concerning symptom needing prompt assessment. The other signs described—varying sleep durations and feeding with weight gain—can occur in healthy newborns or reflect non-thyroid issues, but they do not indicate an immediate respiratory crisis.