Now, a balancing act

It's been just over 11 years since the American Academy of Pediatrics started "Back to Sleep," a campaign designed to reduce the risk of sudden infant death syndrome, or SIDS. The campaign, which promoted the supine -- or back-down -- position for babies during sleep, has been a resounding success: The rate of SIDS in the United States has fallen more than 40% since 1992.

The back-down sleeping position has given rise to an unexpected complication, however: an increase in the number of infants being treated for misshapen heads (known in medical terms as plagiocephaly).

"Because the skull is soft and moldable during infancy, if a child is left in the same position all the time, the side pressed against the bed will become flattened from the pressure," says Dr. Mark Krieger, a pediatric neurosurgeon at Childrens Hospital Los Angeles. Although this type of positional plagiocephaly does not disrupt brain growth or pose any real danger, it can result in significant cosmetic deformities.

A baby who routinely rests squarely on the back of her head may develop flattening in this area and a compensatory fullness across the forehead. A baby who favors resting with her head turned slightly to the right or left might develop a flattening in the back on one side, along with a compensatory bulge above the ear on the opposite side (developing what is often described as a lopsided appearance).

In spite of this possible complication, pediatricians still strongly recommend the back-down position for sleeping at night and for naps.

However, parents can do several things to prevent the development of head molding.

Babies should be allowed a certain amount of supervised "tummy time" during waking hours. This position not only helps prevent head flattening, it also promotes the upper-body strength necessary for important developmental skills such as rolling over, pushing up and crawling.

Also, when infants are on their backs -- whether asleep or awake -- the head position should be alternated to prevent constant pressure from being applied to the same part of the skull. Sometimes the head can be turned slightly to the left and other times slightly to the right. Periodically switching the child's orientation in the crib (putting the feet at the end of the crib where the head usually goes) can help accomplish the same thing. Infants typically turn in the direction of noise or activity; changing crib orientation causes babies to turn their heads to see what is going on.