New research indicates that children may develop some allergies while still in the womb. Is there anything expectant mothers can do to lower the risks?

It’s estimated that allergies affect 40 percent of children in the United States.

Most parents feel powerless to treat these ailments, let alone prevent them.

But what if allergies start before a child is born and we could actually do something to avert their onset or severity?

In recent years, several studies have suggested that allergies could be developed while babies are in the womb.

This might mean that mothers can modify their diets or take supplements in an effort to limit the development of allergies.

Developing allergies involves a “complex interplay of genetic predispositions and environmental factors,” Dr. Stacey Galowitz, an allergist from New Jersey, told Healthline.

“It is known that infants with a sibling, or at least one parent, who has allergic conditions are at an increased risk for the development of allergic disease themselves,” she said.

Dr. Scott Sicherer, a professor of pediatric allergy and immunology at the Icahn School of Medicine at Mount Sinai in New York City, agreed that genetics can play a major role in whether a child has hay fever, asthma, or eczema.

In addition, almost 6 million children under the age of 18 — 1 in 13 kids — have food allergies, and about 30 percent of them are allergic to more than one food, Food Allergy Research & Education reports.

What can an expectant mother do to reduce the chance of her child developing allergies?

Diet may be a good place to start.

“Though there are no current recommendations of specific interventions parents can take to definitively prevent allergies in their unborn child, the majority of publications support maintaining a well-balanced diet throughout pregnancy and lactation, as specific restrictions of key allergens have not been shown to prevent the future development of allergic disease in children,” Galowitz said.

“In fact, some studies suggest that avoiding select foods during pregnancy may actually increase the risk of developing future allergies in infancy or childhood.”

Similarly, the use of prenatal vitamin D, prebiotics and probiotics, and fish oil supplementation during pregnancy has not clearly demonstrated a benefit in the reduction of allergic diseases, Galowitz added.

Sicherer said there are no studies that look at any preconception prevention strategies for allergies.

In fact, there is “no strong rationale to expect that a preconception strategy would be relevant,” he noted.

Women should maintain a healthy diet, but there have been no clinical trials on that theory, as randomizing women into healthy and unhealthy diets would be unethical.

“There is soft evidence that a nutritious, varied diet with healthy fats may help,” Sicherer said.

But there’s been inconclusive evidence that using probiotics, for example, lowered the risk for allergic rashes.

There is some evidence that allergies may be predetermined by several factors.

A 2014 study out of Australia concluded there was preliminary evidence of pre-birth programming of food allergies.

The study was conducted on 12 infants.

As a result, Dr. David Martino of the Murdoch Children’s Research Institute said epigenetics had a role in allergy development. Epigenetics refers to genes being turned on and off due to the environment.

Research conducted last year reported that factors such as maternal cigarette smoking, preterm birth, and cesarean delivery were “implicated in predisposing” babies to allergy development later on in life.

Healthy eating, larger families, and healthy in utero growth were protective, although researchers were not sure how that worked.

A team at the University of Southampton reported last year that there are DNA markers that link a person’s season of birth to developing allergies.

Those born in autumn had a higher risk for having eczema while spring babies had less of a risk.

What about the notion that feeding children small amounts of “trigger” foods can desensitize them to having an allergy to that food?

Some research indicates that introducing previously feared foods such as milk, egg, nuts, and shellfish can decrease an infant’s risk for developing allergies to those foods.

Eczema has already been linked to having a food allergy or sensitivity.

It is important to consult with an allergist prior to introduction of these foods if your child has moderate to severe eczema, preexisting food allergies, or a peanut-allergic sibling, Galowitz added.