New research suggests that children with heavier birth weights may be at a higher risk of childhood food allergy or eczema.
In a meta-analysis, researchers examined data from 42 studies to evaluate whether prenatal growth affects susceptibility to allergy.
The study found that a birth weight increase of 1 kg was associated with a 44 per cent greater risk of food allergy in childhood (odds ratio [OR] 1.44; 95% CI 1.04-1.99; P=.001), a 17 per cent greater risk of ever allergic dermatitis in childhood (OR 1.17; 95% CI 1.04-1.32; P=.008) and a 34 per cent greater risk of ever or current allergic dermatitis in infants up to two years of age (OR 1.34; 95% CI 1.08-1.68; P=.009). Birth weight was not linked with risks of allergic rhinitis.
Meanwhile, the findings suggest restricted foetal growth might protect against some allergic diseases.
"It is increasingly clear that genetics alone do not explain risks of developing allergies, and that environmental exposures before and around birth can programme individuals to increased or decreased risk of allergies," said author Dr Kathy Gatford.
The study is published in the Journal of Allergy and Clinical Immunology.