Lower Birth Weight May Protect Against Allergies
However, effects might differ between allergic diseases
MONDAY, Oct. 21, 2019 (HealthDay News) -- Intrauterine growth restriction protects against allergic diseases, according to a review published online Oct. 12 in the Journal of Allergy and Clinical Immunology.
Amy L. Wooldridge, Ph.D., from University of Adelaide in Australia, and colleagues conducted a systematic literature review to identify studies evaluating the association between prenatal growth and susceptibility to allergy.
The researchers identified 42 eligible studies, including prospective and retrospective cohort, cross-sectional, and case-control studies. Allergic asthma was investigated in only two studies. A 1-kg increase in birth weight was associated with a greater risk for food allergy in children (odds ratio, 1.44), a greater risk for ever allergic dermatitis in children (odds ratio, 1.17), and a greater risk for ever or current allergic dermatitis in infants up to 2 years of age (odds ratio, 1.34). There was no association noted between risk for allergic rhinitis and birth weight.
"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," a coauthor said in a statement.