Individual course of cranial symmetry and proportion in preterm infants up to 6 months of corrected age

IntroductionA significant proportion of preterm infants have dolichocephaly and/or deformational plagiocephaly (DP) at term equivalent age. However, quantitative data on the clinical course after discharge is limited in these infants.AimsTo quantify the individual course of cranial symmetry and proportion in infants born < 32 gestational weeks up to six months of corrected age (CA) and to investigate, whether measurements at discharge predict subsequent cranial deformations.MethodsA total of 56 infants were examined at discharge, three and six months of CA. Cranial proportion and symmetry were quantified using a 3D laser scan method. Classification and prevalence data were obtained using age related reference values. Predictive value of DP at discharge regarding subsequent deformation was evaluated.ResultsCranial Vault Asymmetry Index was 3.9% at discharge, 4.5% at three months and 3.7% at six months of CA. Prevalence of DP was 34% at discharge, 46% at three months and 27% at six months. Cranial Index was 71.4% at discharge and constantly increased over the examination period. Prevalence of dolichocephaly was high at discharge (77%) and subsequently decreased. While severe DP at discharge was predictive for a persistent deformation (PPV 0.78), 46% of infants without DP at discharge developed DP by six months of CA.DiscussionDespite a high prevalence at discharge, the decreased prevalence of DP and dolichocephaly at six months of CA suggests an optimistic course. However, changes in head shape are hardly predictable for the individual infant. Thus, an accurate quantification should be part of neonatal follow-up programs.