A new study at the University of Manitoba, Canada, has found that kids whose mothers suffer prolonged depression or anxiety have a higher rate of asthma than their peers, independent of other risk factors for the increasingly common respiratory condition.
The study, led by Anita Kozyrskyj, Ph.D., Associate Professor in the Faculty of Pharmacy at the University of Manitoba, Canada, appear in the second issue for January of the American Journal or Respiratory and Critical Care Medicine.
Evidence is emerging that exposure to maternal distress in early life plays a causal role in the development of childhood asthma. In a cohort of children born in 1995, we found that maternal distress which persists beyond the postpartum period is associated with an increased risk of asthma at school-age, Dr. Kozyrskyj said.
For the study, Dr. Kozyrskyjs team analysed the medical records of nearly 14,000 children born in Manitoba in 1995 who were continuously registered with Manitoba Health Services until 2003.
They checked to see whether the children had asthma at age 7 by analysing records of doctor visits, hospitalisations and medications in the year of their 7th birthday.
They crosschecked this with the mother's medical records, including doctor visits, hospitalisations and medication for depression and anxiety.
And they ranked maternal distress by the duration of treatment: no distress, postpartum distress only, short-term distress and long-term distress.
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, Dr. Kozyrskyj