Food allergy among low birthweight children in a national survey.

The aim of this paper was to investigate the association between birthweight and prevalence of food allergies using a national sample of US children. Adult report of birthweight and child food allergies were obtained for years 2005-2009 from the National Health Interview Survey (NHIS), a cross-sectional household survey of the US population. A total of 51,748 children aged 0-17 years were included in the analyses representing over 73 million children. Multivariable logistic regression analyses examined associations between birthweight categories and food allergies stratified by age and gender; accounting for the complex design of NHIS. Children aged 6-12 years who were born very low birthweight (500-1,499 g) were more likely to have reported food allergy compared to referent (3,000-3,499 g), OR = 1.72; 95% CI: 1.02-2.91. However, there was no clear trend of an association between birthweight and food allergy with increasing or decreasing birthweight across all ages. Estimates were generally stronger in younger male children as compared to estimates in females of the same age group. Marginal associations for respiratory allergy (OR = 1.52; 95% CI: 1.02-2.29) and hay fever (OR = 1.54; 95% CI: 0.93-2.54) were observed among very low birthweight children aged 0-5 years. There was limited evidence for a clear association between birthweight and food allergy. Marginal associations observed in children weighing 500-1,499 g at birth support efforts to minimize preterm births and very low birthweight given the increase in pediatric food allergies and the large number of children born low birthweight each year in the US.