The push to put babies to sleep on their back to reduce the risk of sudden infant death syndrome (SIDS) has been associated with a decrease in the incidence of SIDS but has led to an increase in the number of babies living with head shape abnormalities. Long hours in the supine position causes prolonged external pressure to an infants head.
Congenital muscular torticollis: This is a deformity resulting from shortening/fibrosis of the sternocleidomastoid muscle (SCM) and is associated with plagiocephaly in almost 90% of infants. Because of this shortening, the infant maintains support of the head on only one side, tilting the head toward the side of the affected muscle and turning the chin to the opposite side.
Multiple fetuses is related to a higher incidence of risk factors, primarily due to the fact that the “crowded” uterus means an intrauterine constraint, a factor related to deformities present at birth. It is believed that when the baby is positioned at a lower position in the uterus, there seems to be a higher risk of developing an asymmetrical skull. As the baby needs to support more weight, the mobility and capacity to change position can adversely predispose to congenital torticollis.
Changes in our current lifestyle may also have contributed to the factors of postnatal deformational or positional plagiocephaly. The use of firm mattresses, frequent use of seats (in the car and for recreation, also known as babybouncers), and swings often cause the baby to stay for long periods in the supine position. The extensive use of the seat accessories would determine a greater potential to deform the skull.