Mother's weight before pregnancy, not weight gained during pregnancy, has impact on development of allergic diseases

A University of Ottawa-led study of nearly 250,000 children in Ontario over seven years—the largest of its kind—found a mother's weight before pregnancy may impact their newborn's risk of developing allergic diseases in early childhood, whereas weight gain during pregnancy did not seem to have the same effect.

Here are the key points from the study, led by Sebastian Srugo, who was a graduate student in the School of Epidemiology and Public Health at the Faculty of Medicine:

• No link found between a mother's weight gain during pregnancy and childhood allergic disease.
• Children born to obese mothers in pregnancy were more likely to develop asthma, but slightly less likely to develop dermatitis and anaphylaxis. Specifically, children born to obese mothers before pregnancy had an 8 percent higher risk of developing asthma.
• Approximately half of the infants were born to overweight or obese mothers and a third to mothers who gained excess weight during pregnancy.
• Mothers are entering pregnancy overweight/obese, gaining excess weight during pregnancy, and many children are developing allergic disease in early childhood.
• In Canada, approximately 30% of the population suffers from at least one allergic disease, with an even greater prevalence among children.
• Globally, trends in allergic diseases have reached epidemic proportions, becoming the most common and earliest-onset group of chronic disease.

The research was published in Paediatric and Perinatal Epidemiology.