Maternal Egg Consumption During Lactation and Risk of Infant Egg Allergy
by Anne Eglash MD, IBCLC, FABM
If a lactating parent eats eggs early postpartum, will that affect the risk of subsequent infant egg allergy?
Egg allergies are common among children, so finding strategies to reduce the risk is important. There is evidence that introducing eggs to infants at 4-6 months of age reduces the risk, yet some infants are already allergic to eggs before that first introduction. The authors of this week’s study investigated whether maternal ingestion of eggs in the first 5 days postpartum would introduce egg tolerance early in life and reduce the risk of infant egg allergy at 12 months of age. The authors describe evidence that the amount of egg protein in human milk is miniscule, so early oral introduction would act like low dose oral immunotherapy.
This was a randomized controlled trial done in Japan that included 380 lactating dyads with one of the infant’s parents having a history of allergies. The reason for this inclusion criteria is that children of parents with allergic disease have a higher risk for developing food allergy.
The researchers excluded infants who were: under 37 weeks gestation; admitted to neonatal intensive care; diagnosed with birth asphyxia; birth weight under 2300g; unable to tolerate breastmilk after day 2 of life; or born to mothers who were diagnosed with an egg allergy.
The dyads were randomized to a maternal egg consumption group where the mother ate 1 egg each day from days 0 to 5 postpartum, vs a control group where the mother eliminated eggs from days 0-5 postpartum.
The researchers measured the existence of egg proteins in the breastmilk of mothers in each group on postpartum day 4 and found that the egg protein levels in breastmilk were significantly higher in the egg consumption group. By 1 month postpartum, there was no difference in the among of egg protein in breastmilk between the 2 groups.
Infant blood tests were done at ages 4 and 12 months to measure IgE antibody levels to egg white, as well as other allergens including cow’s milk, casein, wheat, and gluten.
What else? See the question!
- The infants who had eczema at 1 month of age had a higher risk of egg allergy at 12 months.
- Eczema rates at 4 months of age were higher among the infants exposed to egg protein via breastmilk in the first 5 days of life.
- After maternal egg consumption, the egg protein levels in milk peaked at 12 hours and remained high for 72 hours.
- After maternal egg consumption, the egg protein levels in milk peaked at 3-6 hours.