ATLANTA (CNN) -- New research shows babies who sleep on their backs may have developmental delays in creeping and crawling, but can quickly catch up.

A report, published in the journal Pediatrics, found infants who slept on their stomachs were able to roll over, sit up, crawl and pull themselves up to standing position earlier than infants who slept on their backs.

However, health experts are not recommending parents put their babies to sleep on their stomachs. Instead, researchers said babies should be put on their stomachs or sides while they are awake to help them build upper body strength.

The study of 350 health infants from birth to the time they walked, found that back sleepers were eventually able to reach the developmental milestones within a reasonable about of time.

Since 1992, doctors and health agencies have been encouraging parents to put all babies to sleep on their backs to reduce the risk of sudden infant death syndrome.

The national "Back to Sleep" campaign is credited with the rapid drop in SIDS deaths in recent years.

Despite progress, there is evidence that many parents are still confused or not getting the information they need about how babies should sleep.

SIDS remains the leading cause of death among all infants from one month to 11 months of age. African American and Native American babies are more than twice as likely to die of SIDS as Caucasian infants.

"We find that groups, undeserved groups that have limited access to medical information may still be following older traditions," said pediatrician Lillian Beard. "They may not be getting the message so we still have a lot of work to do."

Parenting Correspondent Pat Etheridge and Reuters contributed to this report.