OTTAWA, Ontario — A mother’s weight before their pregnancy may be the determining factor as to whether her newborn develops allergies later on, a new study reveals. Researchers from the University of Ottawa say babies born to overweight women — before their natural weight gain during pregnancy — face a higher risk of developing asthma.

Allergies are one of the most common ailments, affecting around 20 percent of the population. Around 50 million Americans suffer from various allergies, making it the sixth-leading cause of chronic illnesses in the U.S.

Allergies may be no big deal for those who only experience mild symptoms like watery eyes or a runny nose, but in more severe cases, allergies can be a daily struggle or even deadly in certain circumstances.

In the case of food allergies, estimates show that the number of children hospitalized due to an allergic reaction to a certain food has tripled since the 1990s. Now, scientists have found a mother’s weight before having children could be part of the explanation.

“Studies suggest maternal weight and weight gain during pregnancy may influence fetal immunological development,” study lead author Sebastian Srugo and researchers write in the journal Pediatric and Perinatal Epidemiology.

Mom’s weight can increase allergy risks by 8 percent

The researchers studied nearly a quarter of a million children (248,017) in Ontario, Canada over a seven-year period. Around half of these children were born to overweight or obese mothers, while a third of the mothers only put on excess weight during their pregnancies.

The team did not discover a link between a mother’s weight gain during pregnancy and their newborn’s eventual allergy issues. However, babies born to obese mothers before pregnancy had an eight-percent higher risk of developing asthma during childhood.

Being underweight also increased the baby’s chances of suffering from skin irritations like eczema, the study finds. Trends in allergy-related diseases have reached epidemic proportions, becoming the most common chronic condition.

Researchers say a mother’s body mass index should therefore be a consideration when doctors examine children for allergies. A healthy BMI is generally between 18.5 and 24.9, while anything over 25 falls into the category of overweight, and anything over 30 being obese.

“Interventions to promote normal pre-pregnancy BMI may, therefore, be an important and cost-effective upstream target to ease the epidemic trends of allergic diseases in childhood,” Srugo and the team writes. “Future work should aim to assess the impact of maternal and paternal health behaviors before, during and after pregnancy on this relationship.”

South West News Service writer Tom Campbell contributed to this report.

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