As the prevalence of obesity increases during pregnancy, so does the prevalence of allergies and asthma in children. Some researchers are now suggesting that there might be a link between the two conditions.
In a recent study in China, researchers found that excessive weight gain during pregnancy was linked to a higher risk of allergic diseases in children – including asthma, wheezing, allergic rhinitis, eczema, and food or drug allergies. The research team evaluated 15,145 mother-child pairs between April 12 and June 1, 2019.
Compared to mothers who gained the recommended amount of weight during pregnancy – about 22 to 33 pounds – children whose mothers gained between 33 and 55 pounds had a 13% increased risk of asthma, allergic rhinitis, or food- or drug allergies and a 9% increased risk of developing eczema.
It is believed that allergic diseases occur in childhood around the time of conception. The mother’s body mass index (BMI) before pregnancy, as well as any weight gain during pregnancy, can alter the environment in the uterus and potentially affect the development of the fetus’s immune system. Allergies are the result of the immune system’s reaction to an external substance such as food or pollen.
“In my office we see a lot of patients who are overweight or obese because of their BMI and we advise them on the many risk factors associated with obesity during pregnancy, but we don’t talk about asthma and allergies very often. This study could change the way we advise people, ”said Dr. Ruth Yemane, a gynecologist at the University of Wisconsin-Madison.
Previous studies have been done to determine whether a high pre-pregnancy BMI could be linked to childhood allergies, but little thought has been given to how weight gain during pregnancy could be related to childhood allergies.
“I think this information will change my practice,” said Dr. Yemane told Medical Daily. “I will add this to my recommendation on why it is important to lead a healthy lifestyle while you are pregnant. You should still exercise and eat a balanced diet. When you are pregnant people say you will eat in pairs, but you shouldn’t double your servings. “
The results of the latest study from China support the results of a 2013 study that found weight gain during pregnancy was linked to an increased risk of wheezing in preschool age.
The study took into account, among other things, the mothers’ income, smoking habits, alcohol consumption and family history of allergies.
“We have women in our office who are obese and we don’t often check to see if their children have developed allergies of any kind. Given that we have such a large patient population who are overweight or obese, this could really be a significant thing, “said Dr. Yemane.
Dr. Yemane pointed out that the study suggests a correlation between weight gain during pregnancy and allergies in children – not a cause. More research would need to be done to determine whether one is directly responsible for the other.
“Perhaps obesity causes an inflammatory condition that can lead to the development of allergies. Maybe it’s not so much about weight gain, but about what foods were specifically eaten during pregnancy, ”said Dr. Yemane.
This is the second study published this month by lead author Yiting Chen of Shanghai Jiao Tong University that seeks to uncover a link between allergic diseases in children and maternal behavior. In the first study, researchers analyzed a possible association between allergies in children and sleep, physical activity, and screening time of mothers during pregnancy. While the results show that there is a possible correlation, significance was only found in male children.
According to the American Academy of Allergy, Asthma & Immunology, around 10 to 30% of the world’s population suffers from allergies.
“Even when children are genetically allergic,” Chen told the New York Times, “effective early intervention can reduce the incidence of allergic disease so that children can grow up healthy.”