Features of the WHO Multicenter Growth Reference Study (MGRS)¹

• Specific communities in the study were selected on the basis of
  • High socioeconomic status.
  • Low altitude (<1,500 m/<4,921 f).
  • Low population mobility, allowing for a 2-year follow-up.
  • A minimum of 20% of mothers in the community were already following the international feeding recommendations.
• Study sites had to have a research institution capable of conducting the study.
• Feeding criteria specified that infants had to follow international infant feeding recommendations, including
  • Predominantly breastfeeding for at least 4 months.
  • Introducing complementary foods by at least 6 months but not before 4 months.
  • Continued breastfeeding for at least 12 months (no upper limit on breastfeeding duration).
• Study sites had to have a breastfeeding support system that included lactation consultants to provide support and counseling to all mothers to ensure that any problems with breastfeeding were addressed quickly and that mothers received appropriate counseling on complementary feeding.
• Exclusion criteria included
  • Maternal smoking during pregnancy or lactation.
  • Prematurity (<37 weeks gestation).
  • High gestational age (≥42 weeks).
  • Multiple births.
  • Substantial morbidity.
  • Low socioeconomic status.  
  • Unwillingness of the mother to follow feeding criteria.

WHO collaborated with the United Nations University Food and Nutrition Program, United Nations Children's Fund, CDC, several governments, and others to develop the WHO growth standards to replace the 1977 NCHS/WHO growth reference that had been used in the international community.²

References

¹de Onis M, Garza C, Vicotra CG, Onyango AW, Frongillo EA, Martines J for the WHO Multicentre Growth Reference Study Group. The WHO Multicentre Growth Reference Study: planning, study design, and methodology. Food Nutr Bull 2004a:25 Suppl1:S15-26.

²Grummer-Strawn LM, Garza C, Johnson CL. Childhood growth charts-Commentary. Pediatrics 2002:109(1);141-2