Exploring the safety of at home powdered formula preparation

Abstract

Infant formula is a breastmilk substitute fed to babies when mums are unable or do not want to breastfeed. In the UK, almost three quarters of babies will have consumed infant formula by six weeks of age, and almost all will have by six months (McAndrew et al., 2012). Formula fed babies are at greater risk of gastrointestinal infections than breastfed babies because breastfeeding is protective against infections as it helps babies’ immune systems develop, and because bottles of formula are at risk of bacterial contamination. Bacterial contamination is thought to occur in two ways; first, powdered infant formula (PIF) is not sterile and can contain harmful bacteria, including Salmonella and Cronobacter if not prepared properly (Crawley, Westland & Sibson, 2022), and second, bottles and teats are vulnerable to contamination during preparation (Redmond et al., 2009; Cho et al., 2019). It is estimated that in the UK over 3,000 babies end up in hospital each year, and a further 10,000 are reviewed by GPs, due to gastrointestinal infections which may be attributed to formula feeding (Renfrew et al., 2012). NHS (2019) guidance states that PIF must be mixed with water at a temperature of 70o Celsius (oC) or greater, to kill any bacteria which may be present in the PIF. The use of boiled water from a kettle cooled to at least 70oC is recommended, which is then mixed with the PIF before allowing it to cool further before feeding. This should be repeated every time a bottle is needed to ensure the formula is safe. Bacteria can survive and multiply in formula, even if it is stored in a fridge. NHS guidance also contains steps to minimise contamination of baby feeding equipment, including washing hands, disinfecting preparation surfaces, and washing and sterilising all baby feeding equipment. However, research shows many parents do not carry out all these steps, and a third of parents do not feel confident about preparing PIF (Brown, Jones and Evans, 2020). Furthermore, there has been an increase in UK parents using formula preparation machines and their efficacy has not yet been sufficiently investigated.