Question

A 5-month-old infant with an upper respiratory infection is brought to the clinic. The mother reports that the infant weighed 7 lb (3.2 kg) at birth. Based on the nurse's knowledge of infant weight gain, which current weight would be within the normal range for this infant?

Answer 1

A 5-month-old infant who weighed 7 lb at birth should have at least doubled their birth weight. A normal range weight for this infant would thus be around 14 lb (6.4 kg), indicating typical growth.

Step-by-step explanation:

Normal Infant Weight Gain

An infant's weight is expected to double by 6 months after birth. Given that the infant in the question weighed 7 lb (3.2 kg) at birth, a typical weight gain would be in the range of 14 lb (approximately 6.4 kg). After the initial post-birth weight loss in the first week, when a newborn may lose up to 7% of their birth weight, healthy infants gain about 28 g (1 oz) daily for the first two months, followed by an average gain of 0.45 kg (1 lb) per month.

Considering these growth metrics, by 5 months, the infant should roughly have doubled its birth weight. Therefore, a current weight within the normal range for this 5-month-old infant with a birth weight of 7 lb (3.2 kg) would be expected to be at least twice the birth weight, hence around 14 lb (6.4 kg) would indicate normal growth.