The Consumer Product Safety Commission is warning parents not let a baby sleep in rockers, pillows, car seats, or any other product that holds an infant at an incline -- with their head higher than their feet. The warning comes after the agency studied what happened to babies’ movements and oxygen levels when they were placed in various products and positions. The researcher who did the study for the commission concluded that none of the inclined sleepers her team tested were safe for babies to sleep in.
Source https://www.webmd.com/