Are Allergies Caused by C-Sections?

As rates of food allergies and other allergic conditions continue to increase among children, the search for prevention strategies has taken center stage among researchers.

There are many ingredients that go into the recipe to determine which children will develop allergies and which ones will not. Some of these ingredients are much more important than others, especially parental history of allergies and whether eczema was present during infancy. With all of the great research to date, we still do not fully understand exactly how and why some children develop allergies. Most signs point to a complicated interaction of one’s genetic predisposition with early life environmental exposures.

The DNA we inherit is up to our parents, and their parents, and their parents’ parents. I suppose men and women who have allergies themselves could choose not to have children with a partner who also has allergies, but that kind of takes the fun out of the whole process.

Unfortunately, there isn’t much that pregnant moms can do to prevent their children from developing allergies. Researchers have investigated vitamin D supplementation, use of probiotics, and even maternal diet (Should moms avoid peanuts to prevent peanut allergy? Short answer: No). None of these factors have been shown to prevent food allergies, asthma or eczema in babies.

What About Method of Delivery?

Interestingly, research has shown that babies born by caesarian section have higher rates of food and environmental allergies (not likely eczema, though), compared with those born by vaginal delivery. These have all been association studies, so they cannot directly prove that caesarian sections cause allergies to develop. Nonetheless, a signal is there.

Why Would Type of Delivery Affect the Development of Allergies?

It likely comes down to a relationship we all have with the trillions of bacteria living on and inside us, called the microbiome. Early life exposures alter our microbiome and it is likely that these bacteria then interact with our DNA to turn certain genes on and others off. When babies are born through caesarian section, they are not exposed to the diverse bacterial flora found naturally in the birth canal, thus altering their microbiome.

Should Women Forego C-Sections to Prevent Their Children from Developing Allergies?

As discussed above, there are many factors that ultimately determine which children will have allergies and this is only one possible piece of the puzzle. The decision to have a c-section section should, first and foremost, always come down to whether this is the best choice for the mother and baby.

While we currently have no cure for food allergies, eczema, or asthma, our evolving understanding of the factors involved in the development of these conditions may one day lead to effective prevention strategies.

For more information on c-sections and allergies, listen to our PediaCast.