Caesarean births not linked to increased risk of food allergy

Caesarean births are not linked to an increased risk of food allergy during the first year of life, according to a new study led by the Murdoch Children’s Research Institute (MCRI).

Australia has the highest rates of childhood food allergy in the world, with about one in 10 infants and one in 20 children over five years of age having an allergy to food. MCRI Associate Professor Rachel Peters said the association between mode of delivery and the risk of food allergy has previously been unclear, due to the lack of studies linking accurate food challenge outcomes to detailed information on the type of caesarean delivery.

The new study involved 2045 infants from the HealthNuts study, with data linked to the Victorian Perinatal Data Collection to source detailed information on birth factors. The study found of the 30% of children born by caesarean, 12.7% had a food allergy compared to 13.2% born vaginally. The results were published in the Journal of Allergy and Clinical Immunology: In Practice.

“We found no meaningful differences in food allergy for infants born by caesarean delivery compared to those born by vaginal delivery,” Peters said. “Additionally, there was no difference in likelihood of food allergy if the caesarean was performed before or after the onset of labour, or whether it was an emergency or elective caesarean.”

Peters said it was thought that a potential link between caesarean birth and allergy could reflect differences in early microbial exposure (bacteria from the mother’s vagina) during delivery.

“The infant immune system undergoes rapid development during the neonatal period,” she said. Mode of delivery may interfere with the normal development of the immune system. Babies born by caesarean have less exposure to the bacteria from the mother’s gut and vagina, which influences the composition of the baby’s microbiome and immune system development. However, this doesn’t appear to play a major role in the development of food allergy.”

The findings come as new research, also led by the MCRI, found that 30% of peanut allergy and 90% of egg allergy naturally resolves by six years of age. Peters said these resolution rates are great news for families and even a little higher than what was previously thought.

The results, published in the Journal of Allergy and Clinical Immunology, acknowledged that infants with early-onset and severe eczema and multiple allergies were less likely to outgrow their egg and peanut allergies. Peters said these infants should be targeted for early intervention trials that evaluate new treatments for food allergies such as oral immunotherapy.

“Prioritising research of these and future interventions for infants less likely to naturally outgrow their allergy would yield the most benefit for healthcare resources and research funding,” she said.

Image credit: ©stock.adobe.com/au/Tanawut

Please follow us and share on Twitter and Facebook. You can also subscribe for FREE to our weekly newsletters and bimonthly magazine.