As part of an initial consultation, I ask parents to bring their child’s growth chart. It never ceases to amaze me how each chart and each child is unique. Look around your playgroup, pre school or school and you will see what I mean. Every child is a different size and shape. Even siblings can be different from each other – one tall and slim, the other shorter and stockier. My daughters are a classic example of this. It would be difficult to recognise them as sisters just by looking at them.
Once out of the womb, it’s our genes that mainly control our growth. We all are born with a certain growth potential. However to reach this, we need good nutrition, good health and a stimulating, caring environment in which to grow. This is why health professionals regularly measure an infant’s growth. It is a good indicator of a child’s well being, not only physical but also emotional. However to be useful, the infant needs to be measured accurately and the figures interpreted correctly. This is not as easy as it sounds. Errors in measurement and not understanding how babies normally grow can sometimes lead to unnecessary worry, feed changes, investigations and treatment.
When you plot your infant’s weight and length over a period of time, the measurements may track along a channel in the growth chart. However we don’t expect babies to stay in the same channel. Crossing percentiles for length and weight is common in the first six months and may occur up to one year. Children settle into the channel of their genetic growth potential over the first year. For example a chubby babe whose mother had gestational diabetes and has been over nourished in the womb is likely to trim down with time. A babe whose twin was hogging the placenta usually shows catch up growth. Both catch down and catch up growth is common in the first year. In addition, even babies who enter the world about on their genetic target don’t necessarily grow along one line on the graph.
Big children grow faster than small ones. While only 1.8 kg may separate a small and big baby at birth, by one year of age, the difference can be 4 kg. This is why measurements need to be put on a chart. Putting on an average of 200 grams a week may be too much to expect of a small baby and not enough for a big baby. It may be fine for an average sized baby at two months, but not at nine months. Growth continually changes with age and is different for different babies. The best way to keep track of it is to use a growth chart.
In 2012 the National Health and Medical Research Council recommended that in Australia we use the WHO growth charts for children between 0 and 2 years of age. These charts are based on measurements that were collected from seven countries with widely varied populations, Brazil, Ghana, India, Norway, Oman and the USA. For children above 2 years, the current charts are still in use – those in your child health record.
The next time someone comments on the size of your child, remember that we are all born with the body that nature intended us to have.