A: è Positional plagiocephaly is the medical term for having a flat area on a baby’s head. You are not doing anything wrong and the flattening likely indicates that you are putting him on his back to sleep -- which is doing something right! Putting a baby on his back to sleep was found to reduce the risk of SIDS (sudden infant death syndrome). A flat head and a baby who avoided dying of SIDS is a much better circumstance than the other way around. The head will return to a rounder shape over time if you can keep the baby off the flattened area as much as possible. A good first step is to move toys and place a mirror on the non-flattened side will encourage your baby to keep his head turned to the other side.
If your baby has a neck that seems stiff and he cannot turn his head to the other side, see the pediatrician in case your baby has tight neck muscles on one side (torticollis); physical therapy will help. Your baby's skull is made up of several bones that fuse together over time but sometimes if the fusion happens too early, the skull will have an abnormal shape (cranial synostosis). There are companies that make shaping helmets which lead to a rounder head shape, but the baby will need to wear the helmet at least 23 hours a day and the helmet will have to be reshaped every 2-3 weeks to be sure that proper molding takes place. Depending on whether or not the abnormal head shape could be causing other issues such as visual disturbance (if one eye is becoming higher than the other), this may determine whether or not your insurance company will pay for the helmet process. I have seen locations charge anywhere from $600 to $2500 for the process, and it needs to be started early in infancy for the best outcomes, ideally by 6 months and no later than age 12 months.