Weight for age: percentile
Your child's percentile is , which means that Weight is larger than percent children of the same age and less than the other percent children of the same age.
Length for age: percentile
Your child's percentile is , which means that Length is larger than percent children of the same age and less than the other percent children of the same age.
Head circumference for age: percentile
Your child's percentile is , which means that Head circumference is larger than percent children of the same age and less than the other percent children of the same age.
Growth percentiles are measurements of a child in comparison with other children. The percentiles are usually shown as curved lines on growth charts.
Here is a simpler way to understand:
If your three-month-old daughter is in the 40th percentile for weight, it means 40% of three-month-old girls weigh either the same or less than your baby.The rest 60% weigh more than your baby.
This means that the bigger the percentile number, the bigger the baby compared to other babies that age. If your baby is in the 50th percentile, it means half the children her age weigh more than that number and the other half weigh less than it (1).
Growth charts help in comparing the child’s height, weight, and head circumference with other children of the same age. They help you and the health care provider keep a check on your child’s growth. They also signal if your child has any medical condition.
Boys and girls have separate growth charts as they have different growth patterns. Boys are slightly heavier and taller than girls.
Although each baby is unique and has his or her growth pattern, most healthy babies follow a similar growth pattern. This does not mean that they are of same height and weight, but that they put on weight in proportion to their size and gender.
The growth charts were developed by gathering information from the height, weight, and head-size measurements of thousands of children. The curves on the charts show how many children weigh a certain amount at a certain age (5).
Growth charts are designed to track a baby's growth using three parameters:
• Head circumference
Your baby’s doctor will take note of these parameters. Over time, these measurements show if the baby’s growth is on par with the standard growth rate. If it is equal to the standard chart, it is a good sign that your baby is healthy.
The graph shows the percentile your baby falls in, and how she fares in comparison to other babies her age.
Weight-by-age compares your baby’s weight with that of the other babies of the same age. The percentile tells you what percentage of children weigh less than your child. For instance, out of 100 children, a value of 40% means your child weighs more than 40% children, and less than the rest 60%.
Height-by-age chart compares your child’s height with other children of the same age. The percentile tells you what percentage of children is shorter than your child. For instance, out of 100 children, a value of 40% means your child is taller than more than 40% children and shorter than other 60%.
Head circumference-by-age compares your child’s head circumference based on age. The percentile shows what percentage of children have a head smaller than your child’s. For instance, of 100 children, a value of 40% means your child’s head is bigger than 40% children and smaller than the rest 60%.
Preterm growth charts are available to be used specifically for premature babies. Such growth charts aim to mimic growth that occurs during term pregnancy. The Fenton preterm growth chart, used by many medical professionals, is based on the birth size of infants with confirmed gestational ages in countries including Germany, Italy, the United States, Austria, Scotland, and Canada. The charts begin at 22 weeks, end at 50 weeks, and may be in conjunction with term charts after 40 weeks. They are gender-specific, take the weight, length, and head increments in weekly increments into account, and include percentiles (3rd, 10th, 50th, 90th, and 97th) (6).
Baby growth percentile calculators are usually based on growth charts and curves from international bodies such as WHO. The data includes children of all countries, races, and ethnicities and compares them against a standard. Though this makes the comparison easy, such charts are likely to over-diagnose underweight and stunting in many normal children in developing countries. On the other hand, they may define overweight children as normal, as in modern times, obesity is on the rise (7).
No, a baby percentile calculator cannot accurately predict a child's adult height. This is because the calculators compare a baby's growth to other babies of the same age and gender. However, genetic factors influencing a child's adult height are not considered.
Your baby’s growth curve can show temporary ups and downs that are normal and should not be alarming. Ups may be due to growth spurt and downs can happen due to illness.
However, if these happen for longer periods, then your child’s doctor will examine the baby to check if anything is wrong. If your baby is breastfeeding, then the provider will check if she is latching on correctly. If your baby is on solid foods, the provider may ask about her stool (3).
The health care provider will keep an eye on differences in percentiles. For instance, if your baby is in the 75th percentile for height and 25th for weight, you would be asked to feed your baby well, so she puts on weight.
Therefore, if you have a concern regarding the baby’s growth curve, it is best to see a doctor for advice.
The primary objective of using a growth chart to track baby’s measurements is not to put her on a high percentile curve. It is to ensure that whatever percentile your baby is in, she grows along that curve.
If the curve has fallen, your child’s doctor will advise you on ways to get your baby back to her original percentile. Unless any medical illness or concern is affecting the baby’s growth, all the percentiles are considered normal.
If the baby is premature, your doctor will suggest a different growth chart to track the baby’s growth. This is adjusted as per her age (calculated from due date) but not chronological age (calculated from the date of birth).
Premature and low birth weight babies may start on a low percentile curve. But they usually catch up with their peers by the age of three (4).
Disclaimer: While the growth percentile calculator tells you what growth percentile your child falls in, it is imperative that you consult a doctor before making any changes in the child's diet, exercise regime, etc. You must remember that a percentile value is not the same as actual growth value, but a comparison of your child's growth with other children of that age group. Hence, a doctor would help you best in understanding if there are any developmental delays in your child, and ways of correcting them.