A 4-month-old breastfeeding infant is at the 10th percentile for weight and the 75th percentile for height. How should the nurse interpret this finding?

• A. Milk allergy.
• B. Failure to thrive.
• C. Inadequate milk supply in mother.
• D. Normal growth curve of a breast-fed infant.

Answer: (D)

Growth in infancy is tracked on separate charts for weight and for length, and a baby’s weight percentile can differ from their length percentile and still be perfectly healthy. In a breastfed infant, especially around four months, it’s common for weight gain to be more gradual and for length (height) to be higher or catching up. A four‑month-old at the 10th percentile for weight but the 75th percentile for height is best interpreted as a normal growth pattern: the baby is leaner in weight but growing well in length, with adequate nutrition from breastfeeding.

This pattern doesn’t indicate illness if the baby is feeding well, has normal activity, wet diapers, and steady weight gain over time. Red flags would include a downward crossing of weight percentiles with poor intake or other signs of poor health, but the given data alone fit a normal growth curve for a breastfed infant.