A new study published in The Journal of Pediatrics has found that relatives, friends and babysitters might not be as well educated when it comes to safe sleep practices, reports the Huffington Post.

Researchers looked at more than 10,000 infant deaths and found that 1,375 occurred without a parent present. In these cases, the child slept in unsafe sleep positions, such as on their bellies, and in unsafe sleep environments, such as on a couch or in an area with blankets and toys.

To explain this, researcher Jeffrey Colvin, MD, of Children’s Mercy Kansas City, noted that this could be due to recent developments in safe sleep practices. “A lot of relatives and friends may not be aware that babies are safest on their backs,” Colvin told Science Daily. “They may have raised children before we knew that this was safest.”