The Connection Between Maternal Nutrition and Infant Eczema: What the Evidence Actually Shows

Your baby has eczema. You’re breastfeeding. And now you’re wondering whether something you’re eating is making it worse — or whether eating differently during pregnancy could have prevented it altogether. These are among the most common questions asked by Australian mothers navigating infant eczema, and the answers are more nuanced than either ‘yes, everything you eat affects your baby’s skin’ or ‘diet has nothing to do with it.’

This article examines the evidence honestly: what maternal nutrition during pregnancy and breastfeeding can and cannot do for infant eczema, which specific nutrients have meaningful research behind them, and when dietary changes are genuinely warranted versus when they risk causing more harm than good.

This article is part of the Nella Vosk Breastfeeding Nutrition & Milk Supply: Evidence-Based Guide for Australian Mothers — your comprehensive resource for the full feeding journey.

At Nella Vosk, the intersection of maternal nutrition and infant skin health is central to our CARE SYSTEM™ — because a well-nourished mother, a well-supported gut microbiome, and a thoughtful feeding approach work together in ways that individual interventions alone cannot replicate.

Eczema (atopic dermatitis) is primarily a genetic condition. Children with one atopic parent have approximately a 30 to 40% risk of developing eczema; with two atopic parents, the risk rises to 60 to 80%. The underlying mechanism is a genetic variant that reduces production of filaggrin — the protein that maintains the skin barrier — leaving the skin more permeable to environmental irritants and allergens.

This genetic reality is important context for everything that follows. Maternal nutrition cannot change a baby’s genetic predisposition to eczema. What it may be able to do is modulate the severity, timing, and immune environment in ways that affect how that predisposition expresses. This is a meaningful but more modest claim than the idea that eating the right foods prevents eczema.

Understanding this distinction matters because it shapes realistic expectations. A mother who eats an anti-inflammatory diet, takes probiotics, and consumes oily fish throughout pregnancy may still have a baby who develops eczema — because the genetics were always going to play the dominant role. And a mother who did none of these things may have a baby with beautiful skin for the same reason.

Within the limits of genetic predisposition, the evidence suggests maternal nutrition may influence several dimensions of infant immune and skin development. Note the language ‘may influence’: this is an area of active research, the evidence is still developing, and the effect sizes found in studies are generally modest.

The gut microbiome and immune tolerance

One of the most significant emerging areas is the relationship between maternal diet, the infant gut microbiome, and the development of immune tolerance versus allergic sensitisation. The infant gut microbiome is seeded during birth and shaped by breast milk in the early weeks. A diverse maternal diet supports a more diverse milk microbiome; probiotic-rich foods and supplements during pregnancy and breastfeeding appear to positively influence infant gut colonisation.

The gut microbiome matters for eczema because it plays a direct role in immune system education — helping the immune system learn to distinguish harmless environmental substances from genuine threats. A less diverse or dysbiotic infant microbiome is associated with higher rates of atopic conditions including eczema. This is one pathway through which maternal diet during pregnancy and breastfeeding may affect infant eczema risk, though the research is not yet definitive enough to make specific dietary prescriptions.

Omega-3 fatty acids

Omega-3 fatty acids — particularly EPA and DHA from oily fish and algae — are among the most studied nutrients in the context of maternal diet and infant atopic disease. Their anti-inflammatory properties and role in immune system development make them biologically plausible candidates for eczema risk modification.

A 2023 systematic review found some evidence that higher maternal omega-3 intake during pregnancy was associated with lower rates of eczema in infants, particularly in the first year. The effect was more consistent when omega-3 intake was measured objectively (blood levels) rather than by dietary recall. However, findings across studies are mixed, and the effect is generally described as modest rather than large.

What is clearer: omega-3 deficiency in the maternal diet has documented effects on infant brain and immune development, making adequate intake important regardless of the eczema angle. Australian guidelines recommend two to three serves of oily fish per week for breastfeeding mothers; choosing lower-mercury varieties (salmon, sardines, mackerel) is recommended.

Vitamin D

Vitamin D has immune-modulating properties and is involved in skin barrier maintenance — two functions directly relevant to eczema. Lower maternal vitamin D status has been associated with higher rates of eczema in offspring in some studies, though not consistently across all populations.

Vitamin D insufficiency is common in Australia despite year-round sun, particularly among mothers who are indoors more during the postpartum period, who have darker skin, or who are fully covered for cultural or personal reasons. Testing and supplementing appropriately during pregnancy and breastfeeding is warranted for its established benefits across multiple systems, including potential (if not yet definitive) benefit for infant skin outcomes.

Probiotics

The most robust evidence for any single maternal dietary intervention and infant eczema risk comes from probiotic supplementation. A 2021 Cochrane review found that maternal probiotic supplementation during pregnancy and/or breastfeeding reduced the risk of eczema in infants, with the effect most consistent for Lactobacillus rhamnosus strains. The risk reduction was approximately 22% in meta-analysis, which is meaningful but not dramatic.

ASCIA (the Australasian Society of Clinical Immunology and Allergy) now acknowledges probiotic supplementation as a reasonable consideration for pregnant and breastfeeding mothers at high risk of having an atopic baby (i.e., with a strong family history of eczema, asthma, or hay fever). This is one of the few maternal nutritional interventions with enough evidence to support a specific recommendation.

Probiotic-rich foods — yoghurt (if dairy is tolerated), kefir, fermented vegetables — also contribute to microbiome diversity, though the specific strains and doses in supplement form are more controlled.

What the evidence does NOT support

Just as important as what evidence supports is what it does not. A 2019 Cochrane review found no significant evidence that maternal antigen avoidance during pregnancy or breastfeeding reduces the risk of eczema in children. Specifically, blanket elimination of dairy, eggs, or other common allergens from the maternal diet in the absence of a confirmed infant reaction is not recommended and may cause harm through maternal nutritional restriction.

This is a critical point: the preventive elimination diet does not work and should not be advised. It is distinct from the reactive elimination diet, which is appropriate when a breastfed infant is already showing signs of a specific food sensitivity.

What passes through breast milk

During breastfeeding, food proteins from the maternal diet can transfer into breast milk in trace amounts and reach the infant’s gut. For most infants, this is beneficial: small exposures to food antigens through breast milk appear to contribute to immune tolerance development — teaching the immune system that common foods are safe.

For a minority of infants who are already sensitised to specific proteins, these same trace amounts can trigger or worsen eczema flares. This is a reactive phenomenon in a sensitised infant, not a reason for all breastfeeding mothers to restrict their diets preventively.

Anti-inflammatory dietary patterns

While specific foods are difficult to study in isolation, an overall anti-inflammatory dietary pattern during breastfeeding — characterised by oily fish, colourful vegetables and fruit, legumes, fermented foods, and olive oil, with limited ultra-processed foods and added sugar — likely supports the anti-inflammatory environment of breast milk and the diversity of its microbiome.

This approach also supports maternal wellbeing, which matters in its own right. A mother who is well-nourished, not postpartum-depleted, and not running on processed food and caffeine is better placed to sustain breastfeeding and manage the considerable demands of caring for a baby with eczema.

When dietary modification is warranted

If your breastfed baby has eczema and you are considering dietary modification, the starting point is to determine whether diet is likely to be a contributing factor at all. Estimates suggest that food sensitivity via breast milk contributes to infant eczema in approximately 30 to 40% of babies with moderate-to-severe eczema — meaning the majority of eczema cases in breastfed infants are driven by genetics and environmental factors, not by what the mother eats.

Signs that suggest food sensitivity via breast milk may be a factor include eczema that fluctuates predictably with certain maternal foods, eczema that appears or significantly worsens in the first weeks despite appropriate skincare, and the presence of other food sensitivity signs (mucus or blood in stools, reflux, significant gastrointestinal discomfort).

The practical guide to running an elimination diet safely while maintaining milk supply and nutrition is covered in depth in the article on breastfeeding and food allergies. And for specific guidance on which foods to avoid while breastfeeding an eczema baby, the article on foods to avoid while breastfeeding an eczema baby covers the practical detail.