Could your baby develop plagiocephaly? One expert discusses this common skull deformity.

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It's a big word for a fairly common occurrence: plagiocephaly (pronounced play-gee-oh-sef-a-lee), which is Greek for oblique or slanted head. The condition refers to an asymmetrical skull, and it occurs because of head molding in nearly 20 to 25 percent of babies. Here’s everything you need to know about plagiocephaly – also known as "flat-head syndrome" and "positional molding.”

What is Plagiocephaly?

Babies have soft skulls that can be molded easily. Outside pressure – whether from a bed, a car seat, or the womb – can create flatness on the back or side of the head. Thankfully, though, the consequences of plagiocephaly are primarily cosmetic, and there are no known disabilities associated with the flattened head. In most cases, by time kids are 2 or 3 years old, it's difficult to see any evidence of plagiocephaly, according to James Laughlin, M.D., a pediatrician in Bloomington, Indiana, who is a Fellow in the American Academy of Pediatrics (AAP) and the primary author of "Prevention and Management of Positional Skull Deformities."

Plagiocephaly Causes

Plagiocephaly occurs for a couple of reasons. First, it can happen in utero. "The way the baby may be positioned in the womb can cause some molding of the skull," Dr. Laughlin says. Plagiocephaly may also result if the baby consistently holds his or her head a particular way when lying down. "If they have a preferential way of wanting to laid or be placed, then that can make the molding or flattening of the head as they're sleeping," he says. The shaping generally happens between 2 and 4 months of age.

Skull deformities have been on the rise since the 1990s, when the American Academy of Pediatrics began instructing parents to place babies on their backs to sleep, in an effort to decrease incidents of sudden infant death syndrome (SIDS). While these sleeping guidelines are still relevant, Dr. Laughlin says parents should actively watch for flattening or changes in the shape of the baby's skull, and contact their pediatrician of anything seems amiss.

Aside from Baby’s position in the womb or the crib, plagiocephaly could be a result of other medical issues, including torticollis (shortened or contracted muscles of the neck) and, rarely, craniosynostosis (a premature fusion of the skull bones).

Flat head syndrome occurs more often if the mother is carrying multiple babies, since there’s less room in the womb. Similarly, premature babies have a higher risk because their heads are extremely soft, and they often lie for days or weeks in the neonatal intensive care unit.

Plagiocephaly Treatment

According to Dr. Laughlin, parents can take several approaches prevent plagiocephaly. For example, they can promote daily tummy time and encourage increased head and neck movement. You can also reverse your baby’s direction in the crib often, so she’s not constantly lying on the same side when looking out into the room.

Although baby flat head won’t impact brain development, treatment is sometimes necessary to fix the condition. Plagiocephaly coupled with torticollis (twisted neck muscles) may require physical therapy. Severe cases may call for cranial helmet, which applies gentle pressure on the skull to promote proper growth. You should only use helmets that are recommended and approved by your child’s doctor. Plagiocephaly pillows, which have a rounded-out hollow interior to relieve pressure on the head, are also available on the market – but these since they can increase the risk of SIDS, we recommend avoiding them.