The chest circumference of a term infant is typically what relative to the head circumference?

• A. Approximately 2 cm larger than the head circumference
• B. Approximately 2 cm smaller than the head circumference
• C. Approximately equivalent to the head circumference
• D. Approximately 4 cm smaller than the head circumference

Answer: (B)

In a term newborn, the head is the larger measurement. The chest circumference is usually about 2 cm smaller than the head circumference. This reflects the typical proportion where the head is relatively large at birth while the chest is a bit smaller and grows to catch up with time. Measurements are taken with a flexible tape: head circumference at the widest part of the head, and chest circumference at the nipple line. If the chest were consistently about 2 cm smaller than the head, that fits normal neonatal proportions. If the difference is much larger or reversed, it would prompt further assessment for potential thoracic or cranial concerns.