Mother and Baby A Canadian study has found that young children whose mothers are chronically stressed have a higher asthma rate than peers, regardless of other risk factors.

The lead investigator of the study, Anita Kozyrskyj of the University of Manitoba and colleagues analyzed the medical records of nearly 14,000 children who were born in Manitoba in 1995, who were continuously registered with Mantibo Health Services until 2003. Medical records of the children who had asthma at age 7 were analyzed and related it to maternal distress.

Maternal distress was categorized according to onset and duration into four categories- which distress, postpartum distress only, short-term distress and long-term distress.

The study found that even after controlling for the known risk factors of male gender, maternal asthma, urban location and total healthcare visits, long-term maternal stress was associated with an increase of nearly one-third in the prevalence childhood asthma.

“Unlike existing studies that have measured maternal stress during the first few years only, the longitudinal nature of our health care study enabled us to characterize maternal distress over time to identify whether it continued,” Kozyrskyj said in a statement.