Primary prevention of allergy in infants – What’s new?

Professor Hugo Van Bever

Recently, a new set of consensus recommendations has been published to guide primary prevention of allergy in infants at risk. In this interview, Professor Hugo Van Bever, a paediatric allergist from the National University Hospital, shares insights from the new guidelines and on the role of partially hydrolysed formula in the prevention of infants at risk of allergic diseases.

Could you briefly tell us more about how and why this document was put together?

About 10 years ago, a set of consensus guidelines on the management of food allergy has been drafted. However, in recent years, several well conducted studies have evolved our understanding of allergy and eczema, and thus, we needed to re-assess and re-align our strategies based on emerging data. This new publication1 provides new recommendations for the primary prevention of allergic diseases, mainly of food allergy, based on findings from more recently published studies. This set of recommendations
focuses particularly on approaches that can help prevent the development of allergy among infants that are at risk, i.e. those with at least one allergic parent and/or those with an allergic sibling.

The consensus recommendations were developed and are endorsed by the Academy of Medicine Singapore, the College of Obstetricians & Gynaecologists, Singapore and the College of Paediatrics and Child Health, Singapore. The proposed guidelines are relevant to Singaporean children and to children who have immigrated to Singapore.

What is the role of breastfeeding in preventing the development of atopy?

Breastmilk is unique and “alive” — it contains more than proteins, fats and carbohydrates; breast milk contains immunoglobulins, cells, growth factors, hormones, and prebiotics — all of which are important not just for growth but also for functional development of the brain and the immune system. In the new guidelines, exclusive
breastfeeding during the first 3–4 months is recommended to reduce the risk of eczema
and wheezing in early life. Evidence also suggest that maternal probiotic intake may
have beneficial effects in reducing eczema risk in the child. Hence, mothers of infants at risk of eczema are advised to consider probiotic intake during the last trimester of pregnancy and in the first 6 months of breastfeeding. Some studies suggest that vitamin D supplementation during pregnancy may lower the risk of allergic disease in the newborn; although the evidence for its role in primary prevention of allergy is weak, vitamin D supplementation may be considered in mothers who are vitamin D deficient.

How does mixed feeding, i.e. alternating between breastmilk and formula, impact a newborn’s risk of developing allergies?

The rate of breastfeeding initiation among mothers in Singapore is very high. However, it remains a common practice in many maternity wards to provide newborns with cow milk-based infant formula in the first few days following delivery, frequently to allow mother to rest and recuperate, and also because of the perception that the mother’s milk production is insufficient to meet the infant’s requirements. Current evidence shows, however, that such early supplementation with milk formula during the first few weeks of
life may put breastfed infants at significantly increased risk of developing cow’s milk
protein allergy (CMPA).

Findings from a study conducted in Japan suggest that in cases where breastfeeding during the first 3 days is not possible, mix-feeding with amino acid-based elemental formula may help prevent sensitization to cow’s milk protein.2 Nonetheless emphasis must be placed on educating mothers and healthcare providers on the benefits of exclusive breastfeeding and avoiding unnecessary formula supplementation to reduce the risk of developing CMPA. The role of hydrolyzed formula as a supplement during early life to breast milk in preventing CMPA is still unknown and warrants further research.

In cases where exclusive breastfeeding is not possible, what is the recommended feeding approach for at-risk infants?

If exclusive breastfeeding is not possible, and the infant is at risk of allergies, a partially hydrolyzed formula (pHF) with prebiotics or probiotics is recommended. Current evidence suggests that this may help reduce the incidence of eczema and possibly other types of allergic disease in at-risk infants. However, how pHF helps in reducing atopy
development is still unclear. Researchers purport that the degree and method of hydrolysis, protein source and non-nitrogen components characterize different hydrolyzed formulas and may determine clinical efficacy, tolerance and nutritional effects.3

In addition, early introduction of the two most common allergenic foods — egg and
peanut — should be done one at a time once a baby is able to tolerate solid foods, but no earlier than 4 months. The newly published consensus document offers practical guidance on how these foods can be introduced gradually into the infant’s diet.1

Our understanding of the allergic march in children is still evolving, and we need to monitor the impact of these new guidelines on the prevalence of allergic diseases among children in Singapore.

References: 1. Academy of Medicine Singapore, College of Obstetricians & Gynaecologists, Singapore, and College of Paediatrics and Child Health, Singapore.
Primary prevention of allergy in at-risk infants – Consensus Statement. 2019. Available at: pdf&ofile=Consensus+Statement+on+Primary+Prevention+of+ Allergy+in+At-Risk+Infants+(FINAL).pdf. 2. Urashima M, Mezawa H, Okuyama M, et al. JAMA
Pediatr. 2019; 173(12): 1137–1145. 3. Salvatore S, Vandenplas Y. Nestle Nutr Inst Workshop Ser. 2016; 86:11–27.