Pregnancy & Breastfeeding


Based on current evidence, pregnant women:

Breastfeeding & Food Allergy Prevention

Breast milk is the best nutrition for babies up to 6 months of age. Where there is a high risk of cow’s milk allergy (parent or sibling), mothers establishing breast feeding should avoid using any cow’s milk based infant formula. Studies to date have failed to demonstrate clear evidence that hydrolysed formula may reduce the risk of allergy in high-risk infants (Boyle et al., 2016).

There is no evidence yet, that food allergy prevention can be achieved while a baby is exclusively breastfed.  Current proven methods of food allergy prevention only begin when the infant is introduced to solid foods. Breastfed babies will be exposed to food allergens along with the natural antibodies and immune protection that breast milk also provides.

Based on current evidence, breastfeeding women:

  • should eat a varied and balanced diet in accordance with recommendations which can be found at

Suspicion of Food Allergy in a Breastfed Infant

(that has ever only received breastmilk: no formula, no “top ups” at birth, no food)

The likelihood of an immediate IgE mediated allergy to breast milk leading to anaphylaxis in an infant is low and if it were to occur, typically happens when introducing cows milk formula or on ingestion of a weaning food containing cows milk such as a baby cereal product.

Delayed non IgE mediated food allergy to maternally ingested food allergens is often hypothesised based on the symptoms experienced by the infant and summarised in table 1 below however many of the symptoms below overlap with variants of normal infant behaviour or sometimes other medical conditions.

Table 1 Potential symptoms of non IgE mediated food allergy
  • ongoing itch (pruritis)
  • redness (erythema)
  • moderate/severe eczema
  • painful regurgitation
  • loose or infrequent stools
  • blood and/or mucus in the stools
  • abdominal pain
  • colic
  • food refusal /aversion
  • constipation
  • perianal redness
  • pallor and tiredness
  • faltering growth plus symptoms above
    (with or without significant eczema)
Note: Any of these symptoms on their own are not diagnostic and due consideration should be given to the duration of any of them. It is also essential to outrule all other potential causes for any of these observed symptoms.

Suggested care pathway

  1. If there any skin symptoms, skin care must first be optimised. Refer to Eczema section here.
  2. Where any of the above gut symptoms do not interfere with the normal feeding, sleeping, development, comfort or functioning of an infant and the infant is gaining weight appropriately there is no indication for a maternal food elimination trial.
  3. Where any of the above gut symptoms cause concern about weight or seem consistently to interfere with the normal feeding, sleeping, development, comfort or functioning of an infant, it is essential to outrule all other potential causes for any of these observed symptoms. The underlying cause should be identified and treated as a priority. Common confounders include:
    • atopic eczema
    • gastric dysmotility
    • idiopathic constipation
    • undiagnosed Hirschprungs
  4. A breastfeeding assessment using the Breastfeeding Assessment Tool (BAT) should be performed by a competent person to ensure there is correct positioning at the breast, effective latch, suck and swallow, that this infant is neither overstimulated nor overtired.  All reasonable measures should be taken to support continued breastfeeding, to reduce maternal stress level and to ensure a quality supply.
  5. Once 1 to 4 above have been addressed and in the presence of persistent unexplained ongoing symptoms, it is reasonable to consider a diagnosis of non IgE mediated milk allergy using a time defined targeted allergen exclusion trial as outlined in table 2 below.  When Milk and egg are mostly implicated however it is unlikely that baked/well cooked foods containing milk or egg will be involved. There is no current evidence that other maternally ingested foods like soy, wheat, tree nut, peanut, fish are involved in Non IgE mediated reactions in an exclusively breast fed infant.
    • If both milk and egg are suspected, they should be excluded one by one and not together.
    • If baked/well cooked foods containing milk or egg are not suspected then they should continue to be included in the maternal diet. Only the suspected milk or egg containing food should be eliminated.
    • Any period of exclusion must be followed by a period of reintroduction to confirm a diagnosis.
    • A breast feeding mother requires 1200mg of calcium and 160 micrograms of iodine and 10 micrograms of Vitamin D3 a day on average. Any breast feeding mother that is excluding milk and dairy products will be excluding the main sources of elemental calcium and iodine in the Irish diet. Appropriate dietary supplementation must be considered throughout the exclusion trial.
    • For those where a clear diagnosis has been identified, the mother (or the infant if they have commenced on solid food) should undergo rechallenge every 6-12 weeks.

Table 2: time defined targeted maternal cow’s milk protein or egg exclusion trial


Breastfeeding Diagram

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