(Reuters Health) – While sudden infant death syndrome (SIDS) is extremely rare, babies who live at high altitudes may be more susceptible to it, a study from Colorado suggests.
The SIDS rate for all of Colorado is about 4.2 cases per 10,000 live births, but among infants living above 8,000 feet, it’s 7.9 per 10,000, the study found.
SIDS occurs in babies less than a year old. The deaths can’t be explained after an investigation and autopsy.
“We hope that this study will make families residing at high altitude, and the physicians counseling them, increasingly vigilant about the known risk factors for SIDS in order to minimize risk,” lead study author Dr. David Katz, a researcher at the University of Colorado School of Medicine in Aurora, said by email.
Nationwide, SIDS kills about 4 babies out of every 10,000 live births and is a leading cause of death in infants, according to the U.S. Centers for Disease Control and Prevention
To understand how altitude may impact the risk of SIDS, Katz and colleagues reviewed data for about 393,000 babies born in Colorado from 2007 to 2012, as well as death records from that period.
Overall, 79.6% of the babies lived at altitudes below 6,000 feet, and 18.5% resided at 6,000 to 8,000 feet. Just 1.9% lived above 8,000 feet.
Compared with babies living at the lower altitudes, infants living above 8,000 feet had a 2.3 times greater risk of SIDS, the study found.
To minimize the risk of SIDS, pediatricians urge parents to put babies to sleep on their backs in cribs without pillows, blankets, or soft objects. Public health officials have promoted these practices as part of a campaign called “Back to Sleep.”
Researchers also reviewed another set of records from 1990 to 2012 to assess the impact of Back to Sleep campaigns started in the mid-90s.
From 1990 to 1993, before Back to Sleep, there were about 20 incidents of SIDS for every 10,000 live births. From 1997 to 2012, that dropped to 5.7 per 10,000.
There wasn’t a significant difference among SIDS cases at different altitudes of birth or residence over those decades, suggesting that the Back to Sleep campaign was equally effective across all altitudes in Colorado.
Because the lowest point in Colorado is more than 3,000 feet above sea level, the study doesn’t assess whether SIDS rates differ at even lower altitudes, just as it doesn’t include data from extremely high elevations, the researchers note May 25 in the journal Pediatrics. They also relied on the altitude associated with the mother’s residence at the time of birth, which might not be where the baby lived.
“Although relatively few people in the U.S. reside at high altitudes, more than 63 million people worldwide live above 8,000 feet, the researchers note.”
While the study doesn’t show living at higher altitudes causes SIDS, it’s possible that less oxygen in the air might lead to hypoxia, Katz said.
“Hypoxia is a plausible linking causal factor, and has been demonstrated in infants residing at high altitude,” he said, adding that more research is needed to better understand SIDS.
Regardless of altitude, all families should always follow safe sleep recommendations for infants, which can minimize the risk of SIDS and also prevent accidental injury and deaths from suffocation or strangulation, said Dr. Michael Goodstein, a pediatrics researcher at Pennsylvania State University and director of the York County Cribs for Kids program.
“Do not panic if you live at high altitude,” Goodstein said by email. Take extra care, he said, to avoid risk factors such as soft bedding and letting kids sleep face down, and instead, promote behaviors with a protective effect, such as back sleeping and breastfeeding.
SOURCE: bit.ly/1AtJYUk
Pediatrics 2015.