Maternal Diet Fails to Reduce Infant Egg and Peanut Allergy

Key Points

• A large Australian randomized trial found that higher maternal egg and peanut intake during pregnancy and breastfeeding did not significantly reduce infant egg or peanut allergy at 1 year.
• The trial included 2,137 pregnant women whose infants had a strong family history of allergic disease.
• The high-intake group consumed at least 6 eggs and 60 peanuts per week, compared with no more than 3 eggs and 30 peanuts in the standard-diet group.
• IgE-mediated egg or peanut allergy occurred in 7.8% of infants in the high-intake group versus 8.4% in the standard-diet group.
• The findings support current evidence that maternal allergen consumption alone may not prevent food allergy, while timely introduction of peanut and cooked egg directly into the infant diet remains an important prevention strategy.
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Maternal Diet Does Not Prevent Infant Food Allergy, Trial Finds

Maternal diet during pregnancy and breastfeeding may not prevent egg or peanut allergy in infants, according to a large randomized trial published in the New England Journal of Medicine.

Researchers in Australia tested whether increasing maternal consumption of eggs and peanuts could expose infants to these allergens before they began eating them directly and potentially promote food tolerance.

The PrEggNut trial included 2,137 pregnant women whose fetuses had at least two biological family members with medically diagnosed allergic disease. The findings showed no significant reduction in IgE-mediated egg or peanut allergy at 1 year of age.

Can Maternal Egg and Peanut Intake Prevent Food Allergy?

The researchers recruited women before 23 weeks of pregnancy who planned to breastfeed for at least 4 months. Participants were randomly assigned to either a high egg–peanut diet or a standard diet.

Women in the high-intake group were asked to consume at least 6 eggs and 60 peanuts each week from enrollment through 4 months after delivery or until breastfeeding ended. The standard-diet group consumed no more than 3 eggs and 30 peanuts weekly.

Researchers based the intervention on the concept that fetal and infant exposure to maternal food antigens could influence the development of immune tolerance. Food allergens can reach the fetus through maternal exposure during pregnancy, while breast milk provides another potential route after birth.

However, the results did not demonstrate a preventive effect.

IgE-mediated egg or peanut allergy developed in 83 of 1,066 infants (7.8%) in the high-intake group compared with 89 of 1,064 (8.4%) in the standard-diet group. This difference was not statistically significant.

What Did the Trial Show About Infant Allergy Prevention?

Analyses of individual outcomes also showed no meaningful differences in egg allergy, peanut allergy, sensitization, or medically diagnosed eczema at 4 or 12 months.

The researchers found similar results among women who breastfed for 4 months and showed adequate adherence to their assigned diets. In this subgroup, allergy occurred in 5.6% of infants in the high-intake group and 6.8% in the standard-diet group.

Safety outcomes were also similar. Serious adverse events occurred in 3.6% of women or infants in the high-intake group and 3.8% in the standard-diet group.

The trial had an important limitation: the observed prevalence of egg or peanut allergy was approximately 8%, substantially below the 16% prevalence used for the original sample-size calculation. This lower prevalence may have reduced the study’s ability to detect a preventive effect.

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For HCPs and nurses involved in allergy prevention, the findings suggest that simply increasing maternal consumption of common allergens during pregnancy or lactation should not be viewed as an established strategy for preventing infant food allergy. The authors also highlighted separate evidence supporting the timely introduction of peanut and cooked egg directly into the infant diet according to established infant-feeding guidance.

Source:

The New England Journal of Medicine