Choice of growth charts

Plotting growth parameters during well-baby visits is strongly recommended.  Promoting Optimal Monitoring of Child Growth in Canada: Using the New WHO Growth Charts, a practice guideline for health professionals, was developed collaboratively by Dietitians of Canada, Canadian Paediatric Society, The College of Family Physicians of Canada and Community Health Nurses of Canada. The project includes the full report, executive summary, health professionals’ guide, questions and answers for health professionals and for parents, and set of WHO Growth Charts adapted for the primary health setting for Canada.

The format of the WHO Growth Charts for Canada was revised in March 2014 to address several concerns, including the choice of percentile range curves, and to include weight for age curves over 10 yrs of age, and are now also recommended by the Canadian Pediatric Endocrine Group (CPEG). Find the revised WHO Growth Charts for Canada at www.whogrowthcharts.ca or below on this website.

There are 2 sets:

  • Set 1 uses the percentiles that represent whole standard deviations away from the growth chart median and include the percentile cut-points that the WHO recommends using, that is for infants: the 3rd, 97th and the 85th.
  • Set 2 uses the percentiles that the US Center for Disease Control uses, which health professionals may be used to seeing, as Canada used their charts prior to 2010. They include the 10th, 25th, 75th and 90th, and do not include the 85th.

The RBR website uses Set 1:

BMI calculators

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WHO vs. CDC

The WHO Child Growth Standards were released in April 2006 and were developed using data collected in the WHO Multicentre Growth Reference Study.http://www.who.int/childgrowth/en/ This study followed more than 8,000 children from six countries (Brazil, Ghana, India, Norway, Oman, USA) who were raised under optimal health conditions (exclusive or predominantly breastfed for more than four months, complementary foods by six months, continuation of breastfeeding until at least 12 months, immunized, receiving healthcare, nonsmoking environment). Under these optimal conditions there were only 3% intersite differences, and thus the WHO Child Growth Charts may be used in children of different racial backgrounds. As these WHO growth charts are based on optimal health conditions, they are called growth standards.

In versions of the RBR prior to 2009, the growth charts used were from the United States Centers for Disease Control and Prevention (CDC). http://www.cdc.gov/nchs/about/major/nhanes/growthcharts/clinical_charts.htm  These CDC growth charts are based on the growth of American children without controlling for optimal health conditions and are better called growth references rather than growth standards.

Use of the WHO growth charts results in different prevalence of underweight, overweight and obesity:

0 - 6 months :
WHO charts reflect a heavier sample - due to faster initial rate of weight gain in breastfed compared to formula fed infants, and thus one might expect to see:
Higher rates of under-nutrition
Lower rates of overweight and obesity

Over 6 months :
WHO charts reflect a taller lighter sample- due to slower rate of weight gain in breastfed and ideally nourished children, and thus one might expect to see:
Lower rates of under-nutrition
Higher rates of overweight and obesity