Maternal Egg Consumption & Infant Allergies

Recently published in JAMA Network Open were the results of a randomized clinical trial examining the effects of maternal consumption of eggs during the early neonatal period on the subsequent development of egg allergy. As noted in this article, food allergies have been estimated to affect at least 10% of children, with egg allergies present in approximately 1% of all children in the US. Additionally, some evidence suggests that very early exposure to specific antigens through breast milk may induce allergy; notably ingestion of cow’s milk within the first few days of life was associated with nearly a doubling in sensitization.

In this clinical trial which occurred in Japan, breastfeeding mothers either completely avoided eggs during the first 5 days following birth or consumed one boiled whole egg per day. After 5 days no dietary restrictions remained in place, and the neonates (approximately 180 in each group) were evaluated at 1 year. At least one of the neonate’s parents was required to have a diagnosed allergic condition (such as atopic dermatitis, asthma, allergic rhinitis, etc.) to increase the odds of sensitization among the neonates.

By age 1, the incidence of egg allergy was 9.3% and 7.6% in the egg-consuming vs. elimination groups, respectively, a non-significant difference. However, this study had a variety of limitations, including a possible under-powering to detect a difference, the use of topical corticosteroids to treat dermatitis (which may have suppressed an allergy) and a very short dose and duration of maternal egg exposure. Additionally, there were several significant risks for the development of egg allergy, including cesarian delivery, eczema at one month of age, and detection of ovalbumin in breast milk at days 3-4.