Flattened Skulls: Helmets? Not Much Use; Tummy Time? Quite Helpful

Ever since the “Back to Sleep” program started 15 years or so ago, parents in the U.S. have been advised to put their babies to sleep on their backs--  a position that was said to be preventative of SIDS (see http://childmyths.blogspot.com/2012/04/causes-effects-statistics-and-sids-or.html). More and more (though not all) parents have been following this advice, but have not nearly as frequently been complying with the recommendation for plenty of “tummy time” or the motto of “back to sleep, tummy to play”. As a result, there have been considerable increases in the number of babies who have asymmetrical skulls, deformed by constant pressure in one area—perhaps 20% of infants now have this problem. If unresolved, the flattened head shape will lead to a continuing odd shape, often accompanied by unusually imbalanced positions for the ears. Even though every face has some lack of symmetry (why a double picture of the right side of your face looks rather different from a double picture of the left side), skull deformities can create an unusually asymmetrical face.

Some facts of bone development complicate this situation. Young infants have soft skull bones, whose bony plates have not knit together, and still have some open areas with no skull bones--  the well-known “soft spots”. These characteristics are essential in order for the baby to be born vaginally, as the head needs to be compressed and molded in order to pass through the narrow space formed by the mother’s pelvic bones. As time passes, the bones grow to completion, and pressure can no longer change their shape without breaking them. However, during the first year, the still-soft skull bones can be molded into different shapes when pressure is applied to them in the same way over long periods.

Pressure that changes bone shapes can occur when a baby sleeps in the same position most of the time. Babies who sleep prone (on the tummy) can move their heads to right or left from soon after birth, but babies who sleep supine (on the back) tend to have the head fall to one side under its own weight, and do not develop the muscular strength to move it from side to side for quite a few months. Tummy-sleepers thus do not have constant pressure in one area, but back-sleepers often do. As the skull bones harden, the back-sleepers’ head shapes may harden into the lack of symmetry that has been created by their sleeping positions.

For some years, it’s been thought that if a baby’s head was becoming deformed, the softness of the bones that caused the problem could also be called on to correct it. A specially-created helmet, worn most of the time between 6 and 12 months, could apply pressure on the parts that protruded too much, and leave space for the growth of those that were too flat. (This method had actually been pioneered by indigenous peoples of the Americas, who bound their babies’ heads to create the shapes they thought were beautiful.)

Helmet use was one of those things that “stood to reason”. But did it work? This question was recently investigated in a study reported in a British Medical Journal article (van Wijk, R.M., et al (2014). Helmet therapy in infants with positional skull deformation: Randomised controlled trial. Vol. 348, g2741). They found that the improvements in babies’ skull shape were about the same whether they were given helmets to correct moderate to severe deformations, or just left alone. The parents’ satisfaction with the babies’ appearance was about the same for the two groups. And refraining from treatment was a great deal cheaper and easier for everyone involved. (But it should be noted that none of the babies in this study had any complicating problems like tightness of neck muscles on one side, nor did they have very severe cases of skull deformation.) Incidentally, a New York Times article by Catherine Saint Louis (http://well.blogs.nytimes.com/2014/05/01/helmets-do-little-to-help-moderate-infant-skull-flattening-study-finds/?_php=true&_type=blogs&_r=0) noted reports from parents suggesting that three-quarters of the time, the helmets shifted or rotated on the head, thus failing to provide the specific pressure pattern they were designed for.

This looks as if helmets are not doing the intended job of correcting skull changes in infants. Perhaps a better approach is preventing such changes. How do parents do this but at the same time use the prone sleeping position that is recommended to them? Well, let’s go back to “tummy time”. Babies need to have early and frequent experiences of being in the prone position. When tummy sleeping was the pattern, it was usually suggested that babies be put prone to sleep as soon as the cord fell off, and that’s what I mean by “early” experience. “Frequent” means several times a day, for 10 minutes or more at a time.

Not only does this early and frequent experience of the prone position help prevent constant pressure on one part of the skull, it also enables the baby to develop muscles and motor skills that are much easier to use in the prone than in the supine position. The young baby’s physical characteristics, with its heavy head and legs drawn up under the belly, make it much easier to lift the head  in tummy position than to do the same thing when on the back. Head-lifting leads to getting the forearms up into pushing position and before long enables the baby to get first the head and then the whole chest up and have a good look around--  something that supine-lying babies will have to wait months before they can accomplish and enjoy. They can also see things and eventually reach for them. There are still-unexplored motor skills differences in early infancy for tummy- and back-lying babies, and all the “milestones” you see in the baby books were developed back when most babies slept prone.

The Times article presents some other suggestions for preventing skull flattening, like limiting the time spent in car seats. There’s also a suggestion for repositioning, or changing the side the baby’s head turns after they are asleep. There’s no mention, however, of an old-fashioned technique for this: because very young babies tend to turn their heads toward light, they can be alternated in the direction they lie when put into the crib, so that sometimes they turn left toward the light, other times right. This may keep them from developing a very strong preference for one head position rather than the other.

Let’s go back to tummy time for a minute. Quite a few parents of young babies forget about it for the first busy weeks of a baby’s life--  then they discover that the baby Does Not Like It. Babies learn quickly how things are “supposed to be” and tend to complain when we do something new to them. So, part of the solution here is to begin early. But if you have already waited too long, and baby objects, you need to try to make it comfortable and interesting for the baby. Try putting the baby on a soft pad on a table top, so you can sit in a chair with your face at baby level. Make sure there’s enough light for your face to be seen. Then make this play time as you talk in your high-pitched talking-to-baby voice and make whatever interesting faces usually get baby attention. Just putting the baby down somewhere with a toy or two or a wind-up music box will not do the job that a real live interactive person can do to persuade a back-sleeping baby that the tummy position is a lot of fun. If you make this time your play time, you and your baby can enjoy it together, while also preventing any serious problems with skull flattening.