The Importance of Tummy Time for Baby's Developing Head

New parents protectively swaddling their newborn are typically sent home from the hospital with directions on how to care for their bundle of joy. They're told how to change a diaper, how often to feed the baby, and when to start using a bath.

And then there's one of today's most important directives: Make sure to place the baby on her back when she goes to sleep. Many parents fearing sudden infant death syndrome (SIDS)—the risks of which can be diminished by back sleeping—can go overboard and never put their newborn on his or her belly.

Physicians are pleased that the incidence of SIDS has decreased by more than 40 percent nationally since the American Academy of Pediatrics (AAP) started advising parents in 1992 to put their babies to sleep on their backs. But there has been an unexpected side effect: flat heads. Though there are no national statistics on it, pediatricians say they are seeing an increase in the number of babies with flat spots on their heads.

Flat Heads on the Rise

Dr. William Butler, a pediatric neurosurgeon at Boston's Massachusetts General Hospital for Children, says it's "probably not coincidental" that he's seen a boost in the number of patients with cranial flat spots, a condition which he says is cosmetic. If an infant spends most of his time on his back or with his head in one position, the weight of his head—which is soft and malleable—can temporarily flatten his skull.

"There might be a little more increase in the flatness of the head, but it's not a permanent condition," says Dr. Marian Willinger, a member of the national task force on SIDS and a researcher at the National Institute of Child Health and Human Development.

Treating Baby's Asymmetrical Head

If an infant develops an asymmetrical head, Drs. Butler and Willinger say there are several things parents can do:

• Tummy Time. One suggestion offered by experts is to allow an infant to spend some time on her stomach when she's awake. The AAP suggests, "A certain amount of tummy time while the infant is awake and observed is recommended for developmental reasons and to help prevent flat spots ...." Babies should be strictly monitored when they're on their bellies, Dr. Willinger cautions. "What you don't want to do is put babies on their stomachs in the crib and walk away," she says. (Read more about tummy time specifics.)
• Tummy Play. Certain toys will encourage infants to spend more time on their tummies. There are several such toys on the market. A play quilt, a play mat, or a plastic mirror will keep an infant entertained and on his tummy.