Even good progress can bring some unwanted effects. Teaching parents to put newborns to bed on their backs has cut the rate of sudden infant death syndrome (SIDS), but it has resulted in five times the number of babies with misshapen heads.
Called positional plagiocephaly by healthcare professionals and “flat head” by parents everywhere, this condition comes about because newborns, whose skulls are necessarily soft, spend so much time lying down. When they’re put in the same position all the time, the consistent pressure on the skull causes its shape to change. The condition can also happen in the womb, incidentally, especially when a baby is wedged against his or her mother’s ribs or is sharing space with multiples.
Positional plagiocephaly is more common in babies who sleep well and often or those with unusually large heads. It also shows up in many babies born prematurely.
You don’t need to worry about every little bump or divot, and all heads are asymmetrical. But if you notice a flat side forming on your baby’s skull, you do want to check in with your healthcare provider. For mild cases, the recommendations will probably be much like those that work for preventing misshapen skulls in the first place. Those are:
- Supervised tummy time. Start small, with a minute or two, and build time as your baby’s neck strength builds. Not only is this a good break from the pressure lying down puts on baby’s skull, the neck strength it helps build helps your baby move while he or she sleeps, meaning that the pressure on his or her skull is relieved periodically through the night as your baby shifts.
- Switch crib positions. Babies naturally turn their heads away from a wall, so if your baby’s crib is against a wall, position his or her head at one end one night (or nap) and at the other the next. That keeps the pressure moving from side to side.
- Keep sitting time to a minimum. Long periods in a car seat or infant seat have the same effect as sleeping. The more you can keep your baby’s head free from pressure, the smaller chance of his or her skull becoming misshapen.
In more extreme cases, your baby may need to wear a helmet or head band to help mold the skull back into shape.
As babies grow, their skulls harden and become less malleable. So that means plagiocephaly becomes less and less a risk; it also means that you want to address any flat spots as soon as you notice them.