Such deaths have been most com among black boy babies younger than 4 months, according to the study, published in the February issue of Pediatrics. But, regardless, the message to parents and caregivers stays the same.

"The concern has as much to do with parental behavior," said Dr.. -- Even while the rate of sudden infant death syndrome (SIDS) in the United States has declined, the rate of infant deaths from accidental suffocation in bed has quadrupled, a new study reports. "Infants should always be placed to sleep on their back on a firm mattress, and the sleep surface should be free of pillows, quilts, comforters and stuffed animals." Another issue related to infant deaths is co-sleeping, the term for when a baby sleeps with a parent, sibling or caregiver. "The safest sleep environment for an infant is one that's close to the parent on a separate sleep surface," said study Shapiro-Mendoza, an epidemiologist in the division of reproductive health at the U.S. The authors said the increase might be due to differences in classification rules and methods among medical examiners and coroners.

Centers for Disease Control and Prevention.