Which infant has an abnormal weight?Four infants are being assessed: Infant 1 weighs 6 lb 8 oz, Infant 2 weighs 4 lb 2 oz, Infant 3 weighs 7 lb 8 oz, Infant 4 weighs 8 lb 3 oz.

• A. Infant 1
• B. Infant 2
• C. Infant 3
• D. Infant 4

Answer: (B)

Understanding newborn weight ranges helps identify when a baby’s weight is outside what’s expected at birth. Most full-term babies weigh roughly 5 pounds 8 ounces to about 10 pounds, with an average around 7 1/2 pounds. In this set, one infant weighs 4 pounds 2 ounces, which is about 4.125 pounds and well below the typical lower limit. That makes this infant’s weight abnormal because it falls into the low birth weight category (under roughly 2,500 grams). The other infants—about 6 pounds 8 ounces, 7 pounds 8 ounces, and 8 pounds 3 ounces—are within the normal birth weight range, so their weights are considered typical for a newborn.