SOURCE: University of Calgary

University of Calgary

SOURCE: Alberta Children's Hospital Research Institute

Alberta Children's Hospital Research Institute

December 01, 2016 10:30 ET

Researchers one step closer to understanding SIDS risk factors

CALGARY, AB--(Marketwired - December 01, 2016) - Sudden infant death syndrome (SIDS) is the sudden, unexplainable death of children under the age of one. While rates have significantly decreased due to research and public advocacy, it remains the leading cause of infant death in Canada.

Researchers from the University of Calgary's Cumming School of Medicine are one step closer to understanding how exposure to cigarette smoke increases the risk of SIDS, and how the cumulative effect of high environmental temperatures (caused by factors such as co-bedding and over-wrapping) and exposure to infection also increases the risk. The study findings were recently published in the journal American Journal of Physiology - Regulatory, Integrative and Comparative Physiology.

"It's important to understand how these environmental factors increase risk so we can better alert parents of the potential danger of these situations," says Dr. Shabih Hasan, Professor, Department of Paediatrics, member of the university's Alberta Children's Hospital Research Institute and senior author on the study.

The study exposed animal models to cigarette smoke in utero and subsequently exposed them to infection-causing bacteria and high environmental temperatures when they were born. The study found that the smoke-exposure group had increased temporary interruptions of breathing, higher rates of cytokine (inflammation causing messenger cells from the immune system) production and an increased heart rate when exposed to infection and high environmental temperature.

Researchers also observed that in both the smoking and non-smoking group, increased body temperature and exposure to infection suppressed the heart rate to levels normally only observed in low oxygen environments (experienced in scenarios such as sleeping under a blanket).

While the studies were conducted in animal models, Hasan says these findings are relevant to humans as they are modelled after evidence in human infants who died from SIDS. Currently, one in 2,000 babies in Canada will die from SIDS.

"These findings emphasize the importance of advocating for a safe sleep environment for babies," says Hasan. "This includes avoidance of over-wrapping infants, setting a reasonable room temperature, avoidance of co-bedding, placing babies to sleep on their back and the avoidance of cigarette smoke both during pregnancy and after infants' birth."

Sarah Cormier is an Airdrie mother whose daughter, Quinn Isla, died of SIDS at the age of four months in 2014.

"Our initial reaction was of shock, loneliness and surprise," she says. "SIDS is every parent's worst nightmare and we are now living it. We were aware of the risk factors but it's hard to believe that it still happens and that it happened to us."

Cormier says Hasan's research and any other research investigating the mysteries behind SIDS is welcomed.

"We are hopeful that this is one step closer to finding out what happens to these babies," she says.

Since the 1990s, "Back to Sleep" public advocacy and media campaigns decreased the SIDS rate by more than 50 per cent. However, the rates of SIDS must be further decreased as one infant death is too many. Hasan and his team are certain that more informed infant care practices will further reduce the SIDS rates. Important changes in infant care practice involve the following:

  • "Back to Sleep" position for every sleep.
  • Room sharing is fine but co-bedding or bed-sharing with parents and twins is unsafe.
  • Avoidance of over-wrapping and overheating the room.
  • Not to use a soft mattress and keep cuddly toys, pillows and heavy blankets out of infant's crib.
  • Avoid cigarette smoke, alcohol and illicit drug exposure during and after pregnancy by both parents.
  • Immunize the infant.
  • Encourage breast-feeding.

About the University of Calgary
The University of Calgary is making tremendous progress on its journey to become one of Canada's top five research universities, where research and innovative teaching go hand in hand, and where we fully engage the communities we both serve and lead. This strategy is called Eyes High, inspired by the university's Gaelic motto, which translates as 'I will lift up my eyes.'

For more information, visit Stay up to date with University of Calgary news headlines on Twitter @UCalgary. For details on faculties and how to reach experts go to our media centre at

About the Cumming School of Medicine
The University of Calgary's Cumming School of Medicine is a leader in health research, with an international reputation for excellence and innovation in health care research and education. On June 17, 2014, the University Of Calgary Faculty Of Medicine was formally named the Cumming School of Medicine in recognition of Geoffrey Cumming's generous gift to the university.

For more information, visit, or follow us on Twitter @UCalgaryMed.

About the Alberta Children's Hospital Research Institute
The Alberta Children's Hospital Research Institute (ACHRI) is a multi-disciplinary institute of the University of Calgary, Alberta Health Services and the Alberta Children's Hospital Foundation. Membership encompasses the faculties of arts, education, kinesiology, medicine, nursing, science, social work and veterinary medicine. ACHRI co-ordinates child and maternal health research from bench to bedside with a vision of giving mothers and children the best health care possible. Working together with an incredible breadth of expertise, the institute members are determined to find the causes of disease, advance medical treatments and prevent illness and injury in children.

For more information, visit

Contact Information

  • Media Contact

    Jordanna Heller
    Director of Communications
    Cumming School of Medicine
    University of Calgary
    P: 403.220.2431