Millions of healthy infants may be assessed as growing too slowly because of inadequate international child growth standards, according to nutritionists from Cornell and the World Health Organization (WHO). As a result, many infants are taken off breast milk and given solid foods before they need them, with potentially life-threatening consequences.
In fact, child growth standards -- the set of height and weight guidelines health workers use to assess whether growth is occurring at satisfactory rates for good health -- are inadequate for many young children, not just infants, Cornell experts say.
"Although current growth references for young children have served many useful purposes, we have come to recognize that they have a number of serious drawbacks and are not suitable for healthy, breast-fed infants around the world whose caregivers follow health recommendations," said Cutberto Garza, M.D., chair of the WHO Working Group on Infant Growth. Garza is director of the Division of Nutritional Sciences at Cornell and associate director of the Food and Nutrition Programme for Human and Social Development at United Nations University. Garza also is a member of the WHO Expert Committee established to reevaluate the use of growth standards for different ages.
"We now know that health workers, using the current references, too easily make faulty decisions regarding the adequate growth of breast-fed infants and thus mistakenly advise mothers to supplement unnecessarily or to stop breast-feeding altogether. Given the health and nutritional benefits of breast-feeding, which include helping to prevent severe infectious and potentially fatal diseases, this potential misinterpretation of the growth pattern can have dire results," he said.
For more than five years, two WHO Working Groups on Infant Growth, under Garza's direction, have been analyzing and assessing the current growth references, which were established by the National Center for Health Statistics (NCHS) and recommended by the WHO since the late 1970s. Those growth curves were based on two sets of data, both using samples of American children.
"We found early on that infants who live under favorable conditions and are fed according to the WHO feeding recommendations often grow more slowly than the patterns reflected in the NCHS-WHO international reference," Garza said. "Yet, there are serious dangers of both introducing solid foods too early and, in other cases, of delaying them. The Working Group concluded that the current growth references only accentuate the difficulty of avoiding these extremes rather than helping ensure optimal infant nutritional management."
The Working Group, which also included Cornell statistician Edward Frongillo, authored both a 1994 WHO monograph, An Evaluation of Infant Growth, that details the group's analyses and justification for new references and a 1995 paper in the Bulletin of the World Health Organization on the use and interpretation of those growth standards in infants.
Garza and Cornell colleagues Jean-Pierre Habicht, the James Jamison Professor of Nutritional Epidemiology, and Jere Haas, the Nancy Schlegel Meinig Professor of Maternal and Child Nutrition, also served as members of the WHO Expert Committee that was charged with re-evaluating the use of growth standards for different ages for assessing health, nutrition and social well-being.
In a 1996 issue of the American Journal of Clinical Nutrition (Vol. 64, pp. 650-658), the committee spelled out which standards were still appropriate for each age group. It noted, again, that a new reference, though complex and costly to establish, was needed for infants and children.
"The need for a new international growth reference is becoming a matter of urgency," the committee wrote, "especially in underprivileged populations in whom the optimal nutritional management of infants and young children is key to survival, or at least to preventing severe infections."
Speaking to the World Health Assembly in May and co-authoring an editorial to be published in an upcoming issue of Pediatrics later this year, Garza acknowledges that the construction of a new reference will be extremely complex, costly and time-consuming.
Nevertheless, thanks to the work by investigators all over the world, the WHO Multicentre Growth Reference Study is under way. It will be based on an international sample of infants and children in at least seven sites around the world who are fed by internationally recognized health standards. Initiated in July in Pelotas, Brazil, by Dr. Cesar Victore, the multicenter study should be completed with the new growth curves ready for adoption by 2001.
"With the support of the international nutritional community -- governments, intergovernmental and nongovernmental organizations, research institutions and health professionals worldwide with strong commitments to infant and young child health -- the world will celebrate the arrival of the next millennium with a technically and biologically sound growth reference that will enhance the nutritional management of infants and young children and thus support their improved survival and development," Garza concluded.