Trial of a Maternal Diet Rich in Eggs and Peanuts to Reduce Infant Allergy

Immune responses leading to food allergy may develop early in life, potentially before the introduction of solid foods. Exposures to food allergens in utero and through breast milk have been proposed as a strategy to prevent food allergies in infants, but evidence from randomized trials is lacking.

In this multisite, randomized trial, pregnant women whose unborn child had at least two biologic family members with medically diagnosed allergic disease were eligible to participate. Participants were assigned in a 1:1 ratio to follow either a diet high in eggs and peanuts that included at least 6 eggs and 60 peanuts per week (high egg-peanut group) or a standard (control) egg and peanut diet that included no more than 3 eggs and 30 peanuts per week (standard-diet group), from before 23 weeks' gestation until 4 months postnatally during lactation. The primary outcome was IgE-mediated egg or peanut allergy in the infant at 1 year of age.

A total of 1070 participants were assigned to the high egg-peanut group, and 1067 were assigned to the standard-diet group. There was no significant difference in the percentage of infants with IgE-mediated egg or peanut allergy between the maternal high egg-peanut group (83 of 1066, 7.8%) and the standard-diet group (89 of 1064, 8.4%) (relative risk, 0.93; 95% confidence interval, 0.69 to 1.26; P = 0.65). Safety measures were similar in the two groups.

The ingestion of high amounts of egg and peanut during pregnancy and lactation did not result in a significantly lower risk of the development of egg or peanut allergy in infants by 1 year of age than ingestion of low amounts of these foods. (Funded by the Australian National Health and Medical Research Council and others; PrEggNut Australian New Zealand Clinical Trial Registry number, ACTRN12618000937213.).