NEW YORK (Reuters Health) – Babies born to motherswho are stressed out during pregnancy appear to be increased riskfor asthma and allergies, according to a study presented over theweekend at a medical conference in Toronto.

Stress is like a pollutant that, when “breathed” into the body,may influence not only a mother’s immune system, but her unbornbaby’s as well, Dr. Rosalind Wright, of Brigham and Women’sHospital and Harvard Medical School noted in comments to ReutersHealth.

“There is a lot of evidence to support the notion that negativeexperiences that cause stress get into the body and disrupt immunefunction,” Wright said. This is why people are more likely to catchcolds or the flu when they’re stressed. And, according to Wright’sresearch, mother’s stress during pregnancy can also influence herbaby’s developing immune system.