As your toddler grows and develops, she will add both weight and height to her stature. Growth charts enable physicians and parents to compare an individual child to population statistics of typical children of the same age. Your physician will be able to assess whether your child's weight and height fall within normal ranges.
Genetics and Nutrition
There are many factors that contribute to the growth of children. Nutritional status and genetics are both key factors that affect and determine how a child grows. A child that does not receive adequate nutrition may experience slowed growth and other physical delays. Fortunately, there are few children that are truly undernourished or vitamin-deficient in the U.S.
Growth charts for children are ubiquitous. You've seen them, maybe you've wondered about what the curves and shadings mean. You can download them from the Internet, and some doctor's offices print them out and hand them to parents. Yet you've probably never gotten a good explanation of what those graphs really mean. Parents ask, "Is she growing normally?" but that is very difficult to answer, because the graphs, despite their appearance, don't define "normal." They are just statistical data gathered by measuring many "normal" children, and they represent percentiles, not "normal" and "abnormal."
What Growth Charts Mean
Some growth charts are pink and some are blue, because girls and boys grow differently. There are also charts for babies up to 2 years old and charts for children aged 2 to 18. Both have a lightly shaded curved wedge with a heavy line down the middle flanked by several lighter lines. The heavy line is the 50th percentile. If your daughter's height falls on this line, then she is taller that 50 percent of the girls her age, and therefore she also shorter than the other 50 percent. The other lines represent other percentiles: 2nd through 98th. It is important to note that 2 percent of normal children will be above the 98th percentile and 2 percent of normal children will be below the 2nd percentile. So although half of all children will be between the 25th and 75th percentiles, 4 to 5 percent of all normal children will be "off the curve," but they're still normal.
The growth chart shows that the average 14-month-old boy weighs just over 22 lbs., and 95 percent of boys his age will weigh between 17.5 and 27.5 lbs. The average length of these boys is almost 31 inches, with 95 percent being between 28.75 and 32.5 inches. A 14-month-old girl in the 50th percentile weighs about 18 lbs and the range in weight spans between 15 lbs and 21.5 lbs. The average length of girls is about 30 inches, with the length range spanning 28 inches to 31.5 inches.
What Is "Normal"?
Pediatricians are really looking for "expected" growth, meaning that children grow, more or less, along the same percentile lines and that they are well-proportioned, with the percentiles of height and weight being roughly similar. However, this often doesn't hold true between 9 and 18 months, because the growth exhibited by babies has nothing to do with their eventual height or weight, and those particular months seem to be a "correction phase" when big babies can sometimes become petite toddlers. With overall positive health, a child will grow according to individual genetics.