New research at the University of Calgary shows that smoking while pregnant, as well as thermal stress, can lead to an increased risk of Sudden Infant Death Syndrome (SIDS). Increased ambient temperature such as over-wrapping a baby at night time or increasing the room temperature can affect the baby's pattern of breathing.

Other known contributing factors to SIDS include babies sleeping in a belly-down position and exposure to cigarette smoke. Combining any of these factors with thermal stress may put babies at greater risk.

"Addressing these risk factors through tobacco reduction programs as well as better infant care practices could potentially decrease the incidence of SIDS," says Dr. Shabih Hasan, Professor in the Department of Pediatrics at the University of Calgary Faculty of Medicine who led the study.

To investigate the effects of thermal stress and cigarette smoke exposure researchers exposed pregnant rat pups to increased ambient temperatures as well as cigarette smoke. This is also the first study involving animals to observe the effects of cigarette smoke rather then just nicotine, which is only one of 4,700 known toxins in cigarettes.

The research will be published in the June 1st edition of the American Journal of Respiratory and Critical Care Medicine. The SIDS Calgary Society is greatly encouraged by the study.

"This finding truly takes us one step closer to medically understanding the mystery of the mechanisms that cause SIDS. We want to encourage Dr. Hasan and others with research focused on these mechanisms to continue their work as there are many parents of SIDS babies that are really looking for medical answers," says George Dalekos, chair of the SIDS Calgary Society.

In 1999, Jackie Sillner's seven-month old daughter Brianne died as a result of SIDS. "It can happen to anyone," she says, "research in this area can answer questions and help parents understand what happened."

(China.org.cn edited by Wang Zhiyong May 31, 2008)