In the first year, infants grow how much in length and weight?

• A. 5 inches in length and double birth weight
• B. 10 inches in length and triple birth weight
• C. 2 inches in length and quadruple birth weight
• D. 8 inches in length and triple birth weight

Answer: (B)

In the first year, growth happens quickly in both height and weight as the body develops rapidly to support babies’ needs. By about the end of the first year, infants typically gain about ten inches in length and triple their birth weight. This pattern reflects the rapid acceleration in infancy, with substantial gains in both dimensions.

For context, a newborn is usually around 20 inches long and about 7 pounds, so reaching around 30 inches and roughly 21 pounds by one year fits the common trajectory.

That’s why the option stating ten inches of length increase and tripling birth weight matches typical infancy growth. The other options don’t align with the common pace of length gain or weight gain seen in the first year.