Birthweight could be linked with childhood allergy, according to a recent study by a group of researchers. The study found that higher birth-weight babies, relative to gestational age, were more likely to experience food allergy or eczema in childhood. A link was not found for hay fever.
The research team screened >15,000 studies and identified 42, which they studied in their systematic review. Data on >2 million humans who had allergies were included in the research. Dr Kathy Gatford, University of Adelaide’s Robinson Research Institute, Adelaide, Australia, discussed the study: “We analysed the associations between birth weight, corrected for gestational age, and the incidence of allergic diseases in children and adults.”
Participants included 2.1 million people living with allergic dermatitis (eczema), around 70,000 people who have food allergies, and >100,000 people experiencing allergic rhinitis or hay fever. The sample was mostly made up of young children and the majority were from developed countries, mostly European.
“For each kilogram increase in birthweight there was a 44% increase in the risk that a child had food allergies or a 17% increase in the risk that they had eczema,” outlined Dr Gatford, adding: “it is increasingly clear that genetics alone do not explain risks of developing allergies, and that environmental exposures before and around birth can program individuals to increased or decreased risk of allergies.”
“Although restricted growth before birth (intra-uterine growth restriction) is associated with increased risks of many diseases in later life, it appears to protect a child against the risk of developing allergic responses,” continued Dr Gatford.
The researchers recognised the need for further study in this area to fully explore the link between birthweight and the impact on the immune development, and later susceptibility to allergy. Dr Gatford went on to conclude: “The main message for mums is that big babies are at increased risk of allergy, so mothers with big babies should seek advice on modifying environmental factors to reduce those risks.”