Positional plagiocephaly, or plagiocephaly without synostosis (PWS), can be associated with supine sleeping position (OR: 2.5).113 It is most likely
to result if the infant's head position is not
varied when placed for sleep, if the infant
spends little or no time in awake, supervised tummy time, and if the infant is not held in the upright position when not sleeping.113, — , 115 Children with developmental delay and / or neurologic injury have increased rates of PWS, although a causal relationship has not been demonstrated.113, 116, — , 119 In healthy normal children, the incidence of PWS decreases spontaneously
from 20 % at 8
months to 3 % at 24
months of age.114 Although data
to make specific recommendations as
to how often and how long tummy time should be undertaken are lacking, supervised tummy time while the infant is awake is recommended on a daily basis.