How Does Maternal Nutrition Affect the Fetus?

Throughout pregnancy, nutrients, micronutrients, and certain food components from the mother can cross the placenta and directly influence the development of the fetal immune system. Diet may affect immune balance-particularly the Th1/Th2 Immune Balance-as well as immune tolerance and the likelihood of exaggerated immune responses after birth.

Early immune imbalance is believed to be closely linked to Atopic Dermatitis and other allergic diseases that often appear in the first years of life.

Should Pregnant Women Avoid All Allergenic Foods?

In the past, many pregnant women were advised to avoid foods such as eggs, milk, seafood, and peanuts. However, current research does not support strict avoidance when the mother has no personal history of allergies. There is no convincing evidence that completely eliminating these foods reduces the risk of allergies in children.

On the contrary, moderate exposure may help the fetal immune system “learn” to develop tolerance. Food allergies are considered a trigger only in a certain proportion of children with moderate to severe Atopic Dermatitis. Therefore, excessive dietary restriction may lead to nutritional deficiencies without providing clear benefits.

The Role of Fats and Fatty Acids

The type of fat in a pregnant woman’s diet can also influence a child’s allergy risk. Omega‑3 Fatty Acids-commonly found in marine fish and flaxseed-help regulate immune responses and reduce inflammation.

In contrast, diets high in saturated fats and Omega‑6 Fatty Acids may promote chronic inflammation, which is considered a foundation for many allergic diseases.

Experts recommend that pregnant women consume omega-3–rich fish about two to three times per week while limiting highly processed and oily foods.

Gut Microbiota: The “Teacher” of the Immune System

A diet low in fiber, vegetables, and fruits may disrupt the mother’s gut microbiota. This not only affects maternal health but may also influence the establishment of the infant’s initial microbiome after birth, thereby affecting immune regulation.

Some studies suggest that supplementation with Probiotics or Prebiotics in pregnant women and high-risk infants may help reduce the incidence of eczema. However, supplementation should be guided by medical professionals rather than taken indiscriminately.

What Should Pregnant Women Eat?

Current recommendations emphasize a balanced, diverse diet and discourage extreme dietary restrictions unless medically indicated.

Recommended:

Consume a wide variety of foods, including milk, yogurt, and nuts if there is no allergy
Increase intake of omega-3–rich marine fish (2–3 times per week)
Eat plenty of vegetables, fruits, and whole grains
Ensure adequate Vitamin D intake under medical guidance

Not recommended:

Completely avoiding potentially allergenic foods without medical advice
Consuming excessive processed foods, refined sugars, and saturated fats
Self-imposing strict diets or taking supplements without proper supervision

A Message for Expectant Mothers

Nutrition during pregnancy not only supports the physical growth of the fetus but also helps shape long-term immune health. A healthy, balanced, and varied diet may help reduce the risk of Atopic Dermatitis and other allergic diseases in children.

Most importantly, pregnant women should avoid extreme dietary restrictions. If there are concerns about allergies or relevant medical history, they should consult a physician for appropriate guidance to ensure that both mother and baby receive adequate nutrition.