One of my favorite things about well-child visits with kids of all ages is reviewing growth curves with their family. It\u2019s a privilege to watch a child grow from an infant into a teenager!<\/p>\n
Your pediatrician uses growth curves as a tool to understand your child\u2019s growth. There are different growth charts based on age and gender assigned at birth. The most commonly used growth charts in the U.S. are from the Centers for Disease Control (CDC) and were last updated in the year 2000.<\/p>\n
There are different growth charts for children who have certain medical conditions that affect growth, such as Down Syndrome, to make sure these kids are growing as expected also. In addition, for infants who are born prematurely, growth curves are \u201cadjusted\u201d for the number of weeks early they were born.<\/p>\n
For kids under the age of 2, we usually look at weight, height, and head circumference.\u00a0For kids who are 2 to20 years, we look at weight, height, and Body Mass Index (BMI \u2013 a way to compare weight for height).<\/p>\n
What is a growth percentile?<\/em><\/strong><\/p>\n A growth percentile compares your child\u2019s measurements to those of other children their age. For example, let\u2019s say we tell you your son is in the 85th<\/sup> percentile for height. That means if you were to line up 100 boys your son\u2019s age from shortest to tallest, he would be standing at number 85 in the line, with 84 boys shorter than him, and 15 boys taller.\u00a0During checkups, your child\u2019s measurements are plotted (a dot is put on the chart) for each of these measurements.<\/p>\n \u201cWhat percentile is my infant?\u201d<\/em><\/strong><\/p>\n Honestly \u2013 the percentile itself doesn\u2019t matter much to your pediatrician, and on its own, doesn\u2019t tell us much about how healthy your child is. What we find most helpful is the trend, or line, of points on the growth curve over time. Generally, your child will stay near the same percentile as they grow through their elementary school years. Whether your baby is at the 95th<\/sup> percentile or 5th<\/sup> percentile, if their growth points are\u00a0steady along this percentile over time, it\u2019s reassuring \u00a0that they\u2019re growing as expected.\u00a0If their percentile goes dramatically up or down, something might be affecting their growth that we want to look into further.<\/p>\n For the first 3 months of life, we expect infants to gain approximately 30g (1oz) per day. Most infants double their birth weight by about 4 to 6 months, and then triple their birth weight by 1 year.<\/p>\n \u201cDoes my baby\u2019s big head mean they will be smart?\u201d<\/em><\/strong><\/p>\n Head circumference is different from brain capability. We measure head circumference in kids under 2 to make sure their brains are growing steadily \u2013 not too quickly, and not too slowly. The best way to help an infant\/toddler with brain development is to read, talk, and play with them every day. These activities will help young kids learn lots of new words and skills that will get them ready to start school.<\/p>\n \u201cHow tall will my child be?\u201d<\/em><\/strong><\/p>\n Unfortunately, most parents leave my office without a great answer to this question. Why? While kids usually grow on the same percentile curve when they\u2019re younger, some move up or down during the growth changes of puberty.\u00a0So it\u2019s really not possible to predict a young child\u2019s adult height with much certainty.<\/p>\n One of the few tools we can use is the \u201cmid-parental height,\u201d which gives a genetic prediction of height.<\/p>\n To determine your child\u2019s mid-parental height:<\/p>\n 1.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Add the biological mother\u2019s and father\u2019s heights in inches together.<\/p>\n 2.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Divide this by 2.<\/p>\n 3.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 For girls \u2013 subtract 2.5 inches from #2. For boys \u2013 add 2.5 inches to #2.<\/p>\n This gives us an estimate, but it\u2019s not very accurate. As an\u00a0example, my own mom is 5\u20195\u201d, and my dad is 6\u20191\u201d. The average of those heights is 5\u20199\u201d, so subtracting 2.5\u201d from this would predict my height to be 5\u2019 6.5. But I grew to only 5\u20194\u201d, 2.5 inches shorter than my mid-parental height. Yet the calculation may help your pediatrician understand if your child is growing in the general track predicted by their genetics.<\/p>\n