Flat heads and developmental delay

Parents frequently get concerned about their baby's head shape, most commonly plagiocephaly. This has undoubtedly become more common over the past two decades, with babies now routinely sleeping on their backs. In an otherwise normal baby, most of us will reassure, suggest more ‘tummy time’, and advise against any intervention such as helmets. Is this reassurance justified? Australian researchers undertook a systematic review (Martiniuk A. J Dev Behav Pediatr 2017. doi: 10.1097/DBP.0000000000000376). They found 19 observational studies of sufficient methodological quality, involving children aged 3 months to 10 years. In 13 of these, a positive association with developmental delay was observed. Motor delay was most evident, and seen more in those studies that looked at younger children. Many papers were subject to biases as the assessments were unblinded, and they came from referral centres rather than population studies: however in all of the 5 studies considered to be the strongest methodologically, the association with motor delay was seen.

This review tells us nothing about cause and effect, and it seems likely that babies with pre-existing but undiagnosed motor delay may spend more time on their …