Aims: To assess what is known about the risks associated with errors in reconstituting the present generation of infant formula feeds, and to examine which methods are likely to be safest.
Methods: Systematic review, and examination of the range of infant formula products currently on sale in the UK. Studies from developed countries conducted after 1977 were included. All studies investigating the reconstitution of formula feeds for full term, healthy babies were eligible. Parameters studied were: measures of accuracy of feed reconstitution including fat, protein, total solids, energy content, and osmolality of feed; weight of powder in scoop; and reported method of preparing feed and measuring powder. Formula products were collected from one large UK supermarket in 2002. Number of different types of infant formula preparations available for sale were determined, together with scoop sizes for powdered preparations.
Results: Only five studies were identified, none of adequate quality or size. All found errors in reconstitution, with a tendency to over-concentrate feeds; under-concentration also occurred. Thirty one different formula preparations were available for sale in one UK supermarket, with a range of scoop sizes. Some preparations had never been tested.
Conclusions: There is a paucity of evidence available to inform the proper use of breast milk substitutes, and a large array of different preparations for sale. Given the impact incorrect reconstitution of formula feeds can have on the health of large numbers of babies, there is an important and urgent need to examine ways of minimising the risks of feed preparation.
Breast feeding is the safest way to feed babies. For the majority of babies in all countries it is a perfect source of nutrition (1) and is available, ready-to-feed, via a clean delivery system. Breast feeding protects against infection, (2-4) and has benefits for health in childhood and beyond. (5-7) National and international agencies recognise the superiority of breast feeding and support it unequivocally. (1 8) However, many babies in many countries are not breast fed.
In the UK, in spite of initiatives to encourage more women to breast feed their babies, and to do so for longer, (9-11) over the past 20 years there has been no real change in the proportion of babies who are breast fed at birth. (12) In 2000, by 4-10 weeks of age (the first stage of the most recent national survey), 75% of babies were either exclusively fed on formula milks, or were receiving a combination of breast and formula feeds. (12) These figures, which reflect infant feeding patterns in many westernised populations, highlight the fact that most babies in the UK are fed, wholly or in part, on breast milk substitutes. It is, therefore, important that while attempting to increase the prevalence and duration of breast feeding, (9 13-15) attempts should also be made to minimise the risks associated with artificial feeding.
The most common breast milk substitutes are formula feeds manufactured as dried powders, reconstituted by adding water. Wrongly reconstituted feeds may have serious consequences for babies and during the 1970s there was concern about the apparently high incidence of hypernatraemic dehydration complicating acute gastroenteritis. (16-19) These and other reports (20-25) suggested the problem was due to babies receiving dangerously high solute feeds, in large part a consequence of mothers preparing over-concentrated feeds. Since these studies were carried out, however, there have been changes in the composition of formula milks. National Dried Milk was withdrawn in 1977 and the use of similar formulae based on unmodified dried or evaporated milk is no longer recommended. (26) All infant formulae marketed in the UK now have to comply with compositional guidelines published by the Department of Health, drawn up to ensure artificial feeds are as close in formulation as possible to human milk. (27) There have also been developments in the ways in which formulae are marketed and sold. For example, parents can now buy formula milk as ready-to-feed preparations and in premeasured sachets.
In contrast to the attention received by hypernatraemic dehydration associated with unsuccessful breast feeding, (28 29) there appears to have been no further …