What is a possible explanation for the “jump” in Stan’s length at 3 months of age?What does Stan’s current weight-for-age percentile say about his weight?

Case Study—How Is Stan’s Growth?

Stan, six months old, has been seen by a WIC registered dietitian for concerns with slow growth, every month for the past four months. His length and weight data are as follows:

Age Weight Length
Birth 5 pounds, 8 ounces 18”
2 months 8 pounds, 12 ounces 21”
3 months 11 pounds, 1 ounce 23 ½”
4 months 12 pounds, 8 ounces 23 ½”
5 months 13 pounds, 10 ounces 24 ½”
6 months 15 pounds, 2 ounces 25 ¼”

Stan has been bottle-fed since the second week of life because his mother was concerned she wasn’t producing adequate amounts of breast milk to support his growth.

Questions:
1. Complete the following table using the World Health Organization growth chart :

Age Weight-for-Age % Length-for-Age %
Birth 3rd 3rd
2 months 3rd 3rd
3 months 10th 25th
4 months 10th 10th
5 months 10th 10th
6 months 10th 10th

2. What is a possible explanation for the “jump” in Stan’s length at 3 months of age?
3. Why is it important to take frequent growth measurements when tracking an infant’s growth?

4. What does Stan’s current weight-for-age percentile say about his weight?