Incidence of Nonsynostotic Plagiocephaly and Developmental Disorders

Importance This is the first population-based study quantifying the incidence of nonsynostotic positional plagiocephaly and/or brachycephaly (PPB) in infancy and its association with developmental disorders. Objective To report the incidence of PPB before age 1 year, the incidence of craniosynostosis, and the percentage of children with PPB diagnosed with a developmental disorder by age 7 years. Design, Setting, and Participants This was a retrospective, population-based cohort study of children in the Rochester Epidemiology Project (REP) born in Olmsted County, Minnesota, from January 1, 2008, through December 31, 2012, with follow-up through age 7 years. Data were analyzed from March 2021 to April 2024. Exposure Physical examination detecting cranial deformity. Main Outcomes and Measures The primary outcome was the incidence of PPB. Secondary outcomes were the incidence of craniosynostosis and the percentage of children with PPB diagnosed with a developmental disorder by age 7 years. Results Of 9909 infants (5084 [51.3%] male; 9205 [92.9%] born at term and 704 [7.1%] born preterm) included in the study, 575 had PPB, for a PPB incidence of 5.8% (95% CI, 5.3%-6.3%). The incidence of PPB was 5.3% (95% CI, 4.8%-5.8%) in term infants vs 11.8% (95% CI, 9.4%-14.6%) in preterm infants. The incidence of craniosynostosis was 0.16% (95% CI, 0.09%-0.26%). A developmental disorder was known or suspected in 4.2% (95% CI, 2.7%-6.2%) of infants at the time of PPB diagnosis; among 402 infants with PPB and follow-up through age 7 years, 30 (7.5%; 95% CI, 5.0%-10.7%) had a confirmed developmental disorder by 7 years of age. The prevalence of autism spectrum disorder (ASD) in children with a history of PPB who were followed up to age 7 years was 2.2% (9 of 402 children). Conclusions and Relevance This study found that only a small percentage of the infants had positional head deformity significant enough to be documented and/or referred for subspecialty evaluation, and only a small subset of these children went on to have a developmental disorder in childhood. This information is helpful for counseling families about their child’s developmental risk at time of PPB diagnosis.