CHICAGO - Fisher-Price, a subsidiary of US toymaker Mattel, recalled 4.7 million infant sleepers after more than 30 babies died in them over a 10-year period, according to a statement released late Friday.

The United States Consumer Product Safety Commission (CPSC) said that anyone who bought a Fisher-Price Rock 'n Play sleeper should immediately stop using the product and contact Fisher-Price for a refund or voucher.

According to the CPSC, infant fatalities occurred after the infants rolled from their back to their stomach or side while unrestrained, or under other circumstances.

Fisher-Price stated that it stood by the safety of its products and decided to conduct a voluntary recall "due to reported incidents in which the product was used contrary to the safety warnings and instructions."

On April 5, Fisher-Price and the CPSC jointly issued an alert warning parents and caregivers to discontinue the use of the product. However, the American Academy of Pediatrics urged them to issue an immediate recall, calling the product "deadly."

This recall involves all Rock 'n Play Sleepers which were sold at a price between 40 dollars and 149 dollars since 2009.