Most parents have heard about growth charts, either from research during pregnancy or from those stress filled pediatric visits after their baby is born. In the United States, we are gifted with two sets of growth charts; the WHO Growth Standard for Infant Development and the CDC Growth Chart for Infant Development.
What are they?
Like milestone references, i.e. when most children walk, talk, eat solids, etc, growth charts are simply guide posts along the journey in your child’s young life. These guide posts offer insight and reassurance that your baby is growing normally and advancing at a rate deemed medically healthy. Growth charts can be helpful and even calming to new parents, yet they can also be a source of confusion and angst. Especially when faced with two options!
What is the difference between the Growth Charts?
The main difference between the growth charts is the approach to describing growth. The CDC growth chart represents a growth reference, while the WHO Growth chart represents a growth standard. In plain english, this means that the CDC created their chart based on the average growth of certain children during a particular period of time – from 1963 to 1994, while the WHO represents how most children grow under optimal conditions.
Sound confusing? It is… and it’s not. One says; ‘This is what we found to be normal for most children over a span of 30 years in the USA‘, while the other says, ‘This is what would be normal if EVERYTHING in the situation were perfect.’
So why use two growth charts?
This answer is a bit more complicated, but no less important. The CDC chart deals with facts and measurements found over 30 years in just the United States, while the WHO deals with assessments and averages extrapolated over a multinational subject pool. Both offer insight and value to parents and health professionals, yet it is how they were created that sets the foundation for debate in terms of infant feeding.
During the time frame the CDC growth charts averages from, many, if not most, infants were formula fed. The breastfeeding initiation rates averaged from a low of 24.2% in 1968 to a high of 58.6% in 1994. Note that those are just initiation rates… by the time those infants were 6 months old, the rates dramatically dropped, from a low of 5.7% in 1968 to a high of 29.3% in 1990.
Which one to use?
Considering that many infants across the United States are still formula fed today, even though breastfeeding initiation rates have dramatically improved (83.2% in 2015), knowing how a child grows under these circumstances is vital – hence the use of the CDC growth chart.
Conversely, the WHO formulated their Growth Chart based on the supposition of optimal nutritional conditions – meaning breastfeeding.
This is why, in a nutshell, Lactation Professionals and many Pediatricians use the WHO Growth Chart for Breastfed infants, and the CDC Growth Chart for Formula Fed Infants. Please note that the CDC recommends the use of the WHO Growth Standard for children under the age of 2, regardless of the availability of a CDC Growth Chart for the same growth period.
The WHO growth chart offers a better view of how a Breastfed infant will grow – at least until age 2. After age 2, it is recommended to transition to the CDC Growth Chart for US raised children, as this is based solely on the nutritional outlook and availability of the food and environment in the US – which is markedly different from other areas of the world. Most 2 year olds in the United States are no longer exclusively breastfed, nor should they be, and thus better represented by the CDC Growth Chart at that point.
A note on Growth Charts
When I was a brand new parent, the idea and reality of the Growth Charts, both the CDC and the WHO version, freaked me out. I was so worried about my girls growing and hitting those milestones, both in weight and height. But here is the thing…. charts are just reference points. They are not goals or outcomes – they are reference points. They are not the soul of your child nor the entire picture of their health – and they should not be your entire focus. Some children are smaller and land lower on the curve, while others are larger and peak higher on the scale. This does not mean that the larger child is healthier or the smaller one wasting away. That is the way of charts like this – there is a range. There will always be someone on the high end and someone on the low end.
They are just reference points. Repeat after me. They are just reference points.
They can be important diagnostic tools and serve a medical value, but they are just reference points. They are not the picture of your child… or of your parenting.
Links to Growth Charts
Please click on the following links to get a copy of each growth chart.
The above links will take you to the main pages for each, which will then be broken down into specific charts. Girls, Boys, Head circumference, Length/height, etc.
You may also find the following, interactive, charts helpful.
If you found this article helpful, please be sure to leave a comment and check out some of my other educational articles regarding Breastfeeding and Parenting.