Which of the following statements is true?

• A. When a doctor is checking an infant's growth, they're looking for the weight percentile to be approximately half of the length percentile (e.g. 50^th percentile for length & 25^th percentile for weight).
• B. Between birth & 12 months old, an infant's weight should approximately double.
• C. An infant's length and weight should be checked by a doctor at least once every year.
• D. A healthy infant's length & weight should increase approximately proportionally to each other.

Answer: (D)

Verified step by step guidance

1. Understand that infant growth is typically assessed by comparing weight and length percentiles on standardized growth charts, which reflect how an infant's measurements compare to a reference population.
2. Recognize that the statement about weight percentile being approximately half of the length percentile is incorrect because weight and length percentiles do not have a fixed proportional relationship like that; they should generally track similarly if growth is proportional.
3. Recall that between birth and 12 months, an infant's weight usually triples, not just doubles, indicating rapid growth during this period.
4. Note that infants' length and weight should be monitored more frequently than once a year, often at regular pediatric visits during the first year to ensure healthy growth patterns.
5. Conclude that the true statement is that a healthy infant's length and weight should increase approximately proportionally to each other, meaning as length increases, weight should increase in a consistent and balanced manner, reflecting overall healthy growth.