North:
WHO- 15th percentile
CDC- 3rd percentile
Sky:
WHO- 97th percentile
CDC- 75th percentile
To better understand the numbers I was seeing, I looked for the methods used to create the numbers in the age-to-weight graph for both organizations. I had always assumed (based upon what I had previously read) that the CDC chart was an older chart using data from formula fed babies from the 50's.
Oops, wrong assumption on my part. The data was actually revised in 2000 to more accurately reflect the current (at the time) population of both formula and breast-fed babies. So formula babies are still included in the chart, messing with the results in my opinion, but at least the numbers are a bit more accurate in regards to my children's feeding habits.
The CDC says:
"Breast-feeding is recommended as the feeding method of choice for most full-term infants during the first 6 months after birth and should be continued with the addition of solid foods through the first 12 months (58). The association between breast-feeding and size and growth in infants has been the topic of many investigations. In general, breast-fed infants tend to gain weight more rapidly in the first 2–3 months. From 6 to 12 months breast-fed infants tend to weigh less than formula-fed infants (18,59). These observations have led to recommendations for the development of new infant growth references based on healthy breast-fed infants (18,19,60,61). A study sponsored by the WHO is currently collecting data at study centers in six countries. These data will be used to develop a new international growth reference."
So I carried on over to the WHO website to see how their data was obtained to create a growth charts.
"The WHO Multicentre Growth Reference Study (MGRS) was undertaken between 1997 and 2003 to generate new growth curves for assessing the growth and development of infants and young children around the world.
The MGRS collected primary growth data and related information from approximately 8500 children from widely different ethnic backgrounds and cultural settings (Brazil, Ghana, India, Norway, Oman and the USA).
The new growth curves are expected to provide a single international standard that represents the best description of physiological growth for all children from birth to five years of age and to establish the breastfed infant as the normative model for growth and development."
-homepage of World Health Organization: growth charts
Yea Breast milk! The real normal growth!
But really, my children are not starving in a third world country nor are they bloated out on synthetic formulas. Numbers, sch-numbers. Both North and Sky are healthy and vibrant even with their vastly different growth patterns. The bottom line is that breast milk keeps a baby healthy.
Doctors (and the medical system) should spend more of their time guiding families towards optimal nutrition of children. Educating families on the physical and emotional importance of nursing, explaining how "nursing-on-cue" benefits both mother and child, increasing milk supply when needed, taking steps to insure a comfortable culture in which a mother can feed her child, all these things and more will lead to a better health of our children and adults.