Paediatricians use growth charts to track a child's progress. These measurements are used to compare the child's growth with what is deemed normal for that child's gender and age. Growth charts are based on information collected by the National Center for Health Statistics. If a child is considered in the 50th percentile height-wise, according to the growth chart that means he is average and half the children his age and gender are taller and half are shorter. If he is in the 90th percentile, he is tall for his age and gender. Ninety per cent of his peers or nine out of 10 are shorter than he is and 10 per cent are taller, or one out of 10.
When a doctor is charting your child's growth, he will measure the child's weight, height, body mass index and head circumference. Inches or centimetres are used to calculate and document a child's length (for infants) or height. Pounds, kilograms or grams are used to determine a child's weight. The weight is based on the infant's age, in terms of weeks or months, and in years for older children.
Measuring Height and Weight
When measuring the height of a child under the age of 3, it is done while he is lying down; older children are measured while standing. A child's weight and height are graphed by his doctor until he is 20 years old.
Head Circumference and Ramifications
The size of an infant or young child's head can reveal if there are problems. Abnormal growth of the head during the first year and one half of his life can be an indicator of a medical problem of some kind. The doctor measures the head size by using a measuring tape and placing it above the child's eyebrows and around the back of his head. When a child is suffering from water around the brain this can make the head grow too fast. This condition is called hydrocephalus. An abnormally large head, which is called macrocephaly, is the result of certain medical conditions including a brain tumour. If the head is growing too slowly this can be the result of the bones of the skull fusing too early.
Body Mass Index
A child's body mass index is measured beginning at the age of 2. This measurement is used to screen for overweight issues. Using this tool is a good way to identify obesity and help prevent it.
After the doctor takes the child's measurements he compares it with the normal or standard range for children of the same sex and in the same age group. If the measurements are too small or too large this may indicated that there is a medical problem.
If an infant or child is not gaining weight sufficiently and his height or a combination of height and weight is in a low percentile this could mean that the child is failing to thrive, is neglected or has a serious illness.
Everyone is different so each child will grow according to his genetics unless there is a medical condition that is affecting his growth. A growth chart does not accurately foretell what a child's ultimate height is going to be.