The back-to-sleep movement for babies has been around for more than 10 years. Since it started, the number of SIDS deaths has dropped by half. But all that time spent on their backs has caused other problems for babies. Now doctors are updating the back-to-sleep campaign with some new advice.

It's sleepy time, and little Michael Joseph is on his back. But come playtime -- he's on his tummy ... Even if he doesn't like it very much. His mom Crystal Delo does everything in her power to keep her 7-week-old son safe.

"Every class we went to in the hospital, they made sure to tell us that babies sleep on their back," Crystal said.

In 1992, the Academy of Pediatrics started telling parents to put babies to sleep on their backs to reduce the risk of sudden infant death syndrome.

"We had about a six-fold increase in the incidence of flat head on the back," said Kim Manwaring, M.D., a neurosurgeon at Phoenix Children's Hospital. In fact, nearly one in 50 babies has significant flattening of their heads. Usually, it's just a cosmetic issue. But some babies are so affected that they need special helmets to re-shape their heads.

It's actually babies who sleep better are more at risk for this flatness. Since 1992 though, more children have had to wear helmets to reshape their heads later.

"You imagine a baby who wakes up and has to be consoled or fed every couple of hours; the baby is positioning frequently and doesn't develop the misshapen head," Dr. Manwaring said. He also mentioned that children who spend all day on their backs may not develop the same coordination as infants who play on their stomachs. "The new guideline we're trying to get out there to parents is supine to sleep -- that means on your back -- but prone to play."

Start with two to three minutes of tummy time three or four times a day, and gradually increase as your baby builds up strength.

It's a little tiring, but Michael Joseph is getting strong and staying safe.

While the number of deaths attributed to SIDS has dropped, the number of infants who died while sleeping on a sofa with a parent has increased. The best way for your baby to sleep is in a crib, on his back, with no pillows, blankets or stuffed animal toys.

SUDDEN INFANT DEATH SYNDROME:

The good news is there has been a major decrease in the number of children dying of sudden infant death syndrome (SIDS). The American Academy of Pediatrics recently released a statement saying their "Back to Sleep" campaign, which urged parents to place infants on their backs to sleep, contributed to the decline. In 1992, the SIDS rate in the United States was 1.2 deaths per 1,000 live births. In 2001, the SIDS rate was .56 deaths per 1,000 live births. But the fact remains, infants are still dying deaths that are hard to explain. The best the medical community can do is offer up the risk factors that are most commonly linked to SIDS. Based on these risk factors, the American Academy of Pediatrics makes the following recommendations:

• Back to sleep: Infants should be placed wholly on their backs for sleep
• Use a firm sleeping surface: Pillows, quilts, comforters, and sheepskins should not be placed under a sleeping infant. A firm mattress covered by a sheet is the recommended surface
• Keep soft objects and loose bedding out of the crib
• Do not smoke during pregnancy
• A separate, but nearby sleeping arrangement is recommended: Sleeping in the same bed or on a sofa together has been shown to be very dangerous and can lead to suffocation deaths
• Pacifiers have been shown to reduce the risk of SIDS
• Avoid overheating
• Encourage tummy time to prevent the development of positional plagiocephaly, the malformation of the head caused by excessive time spend in the supine position

PRONE TO PLAY:

Prone means lying with the front of the body facing downward. For infants, this means "tummy time." The American Academy of Pediatrics encourages parents to let their children spend time on their stomachs each day. This may help stop the development of a flat head. Too much time in car seat carriers and bouncing chairs also place pressure on the back of the head, contributing to this problem. Pediatricians say there is a fear among some parents that any time of the stomach will cause SIDS. But supervised time on the stomach can also enhance motor development.

The American Academy of Pediatrics has other recommendations to help prevent your child from developing a flat head:

• Change the position of the head during sleep weekly
• Change the position of the child relative to outside activity. The child is likely to look toward a door.