Relationship between maternal egg consumption during lactation and the risk of developing egg allergies in 12-month-old infants: A multicenter cohort study.

Aim: To determine the effect of maternal egg consumption during lactation on the development of egg allergies in 12-month-old infants. We hypothesized that infants whose mothers consume larger amounts of eggs during the early lactation period acquire oral immune tolerance and are less likely to develop egg allergies at 12 months.

Methods: This study was a part of the Japan Pregnancy Eating and Activity Cohort Study. Mothers answered questionnaires on egg consumption, breastfeeding rates at 1 month, infants' eczema at 6 months, and the development of egg allergies among infants at 12 months. In order to assess the actual impact of maternal egg consumption on infants' egg allergy development, breastfeeding-dependent egg consumption was calculated at 1 month by multiplying maternal egg consumption at 1 month with the breastfeeding rates at the same time. Logistic regression analysis was performed to examine the potential risk and protective factors.

Results: Data from 420 infants were analyzed, of whom 27 had egg allergies at 12 months. No significant impact of breastfeeding-dependent egg consumption was observed on infants' egg allergy development at 12 months. However, infants with eczema at 6 months showed a greater risk of developing an egg allergy at 12 months (adjusted odds ratio, 3.59; 95% confidence interval, 1.59-8.13).

Conclusion: The results suggest that breastfeeding-dependent egg consumption at 1 month did not contribute to sufficient oral immune tolerance in 12-month-old infants. Eczema at 6 months significantly impacted the development of an egg allergy, emphasizing the importance of preventing cutaneous exposure to egg allergens.