Caesarean delivery increases risk of childhood food allergies
Infants born through caesarean delivery appear to be at higher risk of food allergies, while those born very preterm have lower risks, a recent study has found.
Using prospectively recorded data from healthcare registries, researchers analysed 1,086,378 live births in Sweden from 2001–2012. Cox regression analyses were performed to determine the relationships between perinatal characteristics and food allergies, as defined by the National Patient Register.
Over the 13-year study period, 2.5 percent (n=26,732) of children were reported to have food allergies. The median age at first diagnosis was 1.6 years and the median follow-up was 6.4 years.
Food allergies were significantly and positively correlated with caesarean delivery (adjusted hazard ratio [HR], 1.21; 95 percent CI, 1.18–1.25), both elective (adjusted HR, 1.18; 1.13–1.23) and emergency (adjusted HR, 1.24; 1.19–1.29).
Similarly, the odds of the development of future food allergies were significantly elevated in babies born large for gestational age (adjusted HR, 1.15; 1.10–1.19) and with low Apgar scores (adjusted HR, 1.22; 1.10–1.36).
On the other hand, the risk of food allergies was significantly lower in infants born very preterm (adjusted HR, 0.74; 0.56–0.98). No such effect was observed for those born moderately preterm (adjusted HR, 0.96; 0.90–1.03) or post-term (adjusted HR, 1.01; 0.97–1.06). There was no link between small for gestational age and future food allergies.
The main methodological limitation of the study is its failure to control for particular important potential confounders such as breastfeeding and antibiotic use, said researchers.