AAP approved chart. I belong to a pediatric ipa/our chart is based on american academy of pediatric recommendations.
WHO growth chart. The who developed growth standards to describe normal child growth from birth to 5 years under 'optimal' environmental (nutritional) conditions. Some breastfed babies may be mislabeled as underweight when their weights are plotted on CDC growth chart but not on who's. This is because the who standards were derived from multiple countries including those that have a lower obesity rate than theus.
WHO. Under 23 months the aap, national institutes of health and the CDC all recommend to use the who growth charts which describe a standard of growth for children under optimal conditions (which means a breastfed infant). After 23 months the recommendation is to use the CDC charts which are a growth reference, describing how certain children grew in a particular time and place.