Growth of breastfed babies
Childhood obesity and its prevention is much on the minds of parents and health providers. The health consequences of "over" nutrition, such as increased cardiovascular disease, cancers and diabetes, are eliciting increased scrutiny about infant feeding and its relationship to childhood obesity. One area of concern seen to be contributing to "overfeeding" has been the use of growth charts commonly used to monitor a baby’s progress. Growth charts are for the most part based on studies of formula-fed babies. It is now well known that formula-fed babies grow faster and follow a different growth pattern than breastfed babies. Using the standards1 of a predominantly formula-fed population and applying this to the breastfed infant may seem illogical. Nevertheless, this has been the practice for decades and plainly reflects the long-held illusion that breast and formula-fed infants grow and develop in a similar fashion.
Additionally, the use of growth charts based on formula-fed infants have been a cause for much needless worry of milk adequacy for mothers and parents of breastfed infants. How many parents were unnecessarily told their infants were not thriving and needed formula supplementation when their babies were compared to the charts of formula-fed infants? How many mothers stopped breastfeeding because they were led to believe their infants were not gaining weight fast enough?
Breastfed infants are the biological norm, states Dr Mercedes de Onis, head of the WHO’s growth reference studies.
The need for growth standards for breastfed infants has been on the WHO’s agenda for a number of years. Recognizing that growth references are a valuable tool to assess a child’s physical progress, the WHO set up a working group in 1993 to begin the development of growth references for healthy breastfed infants. Subsequently, the WHO set up it’s Multicentre Growth Reference Study (MGRS).2 At the same time it also needed to recognize a number of factors that could signi.cantly affect physiological growth such as the timing of complementary feeding, various socio-economic factors, and differing growth patterns among breastfed infants.
Preliminary studies were needed to work out the impact of these potential variables. The first published results3 established that growth patterns were remarkably similar in the first seven countries studied (Australia, Chile, China, Guatemala, India, Nigeria, and Sweden). Except for China, where infants were found to be slightly shorter, and India where infants were 15 per cent lighter at 12 months of age. Despite these regional differences, the study coordinating team concluded that breastfed infants grow very similarly, even when they are from diverse ethnic backgrounds and geographic locations.
Although the WHO growth references are not yet publicized, some results of the MGRS have been made available to the press.4
The WHO MGRS studied 8,440 children from six countries (Brazil, Ghana, India, Norway, Oman, and the USA ) and is contributing some very useful information.
The existing weight requirements for two and three-year-olds were 15 per cent to 20 per cent too high.■
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The formula-fed standard put a healthy one-year-old between 22.5 lbs and 28.5 lbs, whereas the healthy breastfed infant weighs in at between 21 to 26 lbs.■
The differences in growth rates and patterns between formula-fed and exclusively breastfed infants already become evident by two to three months of age.■ The survey’s highly compelling results show that it is not the breastfed infant who is not growing well, but the formula-fed infant who is fed too much.
According to Dr. Mercedes de Onis, coordinator of the WHO study team, "The new standards provide a much better description of the physiological growth and they establish that breastfed infants are the biological norm. Paediatricians will be able to congratulate parents on having exclusively breastfed their infants instead of spending time, as they do now, in trying to reassure them that the apparent growth faltering of the baby is not a reason for concern and is due to the imperfections of the growth charts that are being used for their growth."
She also noted that the highly anticipated WHO growth references would be released at the end of the year.
Also commenting on the results was Dr Prakash Shetty, head of nutrition planning at the UN's Food and Agriculture Organisation, who said, "The new recommendations mean that daily energy intake for babies should be about seven per cent less than current levels."
Avoiding overfeeding and easing the concerns of mothers regarding the growth rates of their exclusively breastfed infants is paramount. Normal growth standards are urgently needed and we look forward to WHO expediating their release.
1. National Center for Health Statistics. Growth curves for children birth-18 years of age, United States, Vital and Health Statistic. Series 1, No. 165, Department of Health, Education and Welfare Publication No. 78-1650, Washington, DC; US Government Printing Of.ce, 1977 [Return]
2. WHO Working Group on Infant Growth. An evaluation of infant growth. Geneva, WHO, 1994 [Return]
3. WHO Working Group on the Growth Reference Protocol and the WHO Task Force on Methods for the Natural Regulations of Fertility. Growth patterns of breastfed infants in seven countries. Acta Paediatrica 89: 215-222, 20000 [Return]
4. The Scotsman, 5 Feb. 2005. http:/news.Scotsman.com/index.cfm?id=136862005 BBC NEWS 4 Feb. 2005. http://news.bbc.co.uk/go/pr/fr/-/1/hi/health/4236229.stm [Return]