Smartphone applications paired with sensors to monitor babies’ vital signs may appeal to parents anxious to make sure infants sleep safely through the night, but there’s no medical evidence proving these products work, a new paper suggests. 

These apps linked to sensors in babies’ socks, onesies, leg bands and diaper clips are marketed as tools to help parents keep tabs on things like breathing, pulse rate and oxygen levels in the blood and sound alarms when infants are in distress. But they aren’t tested or approved for US sale like medical devices and there’s little evidence to suggest these monitors are safe or effective, said Dr. Christopher Bonafide, lead author of the opinion piece in JAMA.

“There is so much anxiety during those first few weeks with a new baby at home, and anything that seems like it might help reduce that anxiety seems incredibly appealing,” said Bonafide, a pediatrics researcher at the University of Pennsylvania and Children’s Hospital of Philadelphia, said by email. “The problem is that a vital sign monitor is not the solution.”