Changing epidemiology of nonsyndromic craniosynostosis and revisiting the risk factors.

Recent studies in Europe and the United States report increased incidence of metopic synostosis. Whether a similar trend had occurred in Australia remains unknown. This research aimed to determine changes in incidence and subtypes of craniosynostosis in Victoria and to identify perinatal risk factors. A retrospective audit of patients (n = 522) presenting to the Royal Children's Hospital in Melbourne with nonsyndromic craniosynostosis from 1982 to 2008 was undertaken. Perinatal data were sourced from the Victorian Perinatal Data Collection. The changes in incidence of craniosynostosis subtypes were calculated based on Poisson regression, and risk factors for craniosynostosis and subtypes were analyzed by univariate logistic regression analysis. The prevalence of nonsyndromic craniosynostosis was 3.1 in 10,000 live births in Victoria. On average, the incidence of nonsyndromic craniosynostosis increased by 2.5% per year among Victorian live births. Over 25 years, metopic synostosis incidence significantly increased by 7.1% per year in the population of Victoria, outpacing other subtypes. The risk factors for metopic synostosis include being male, multiple births (ie, twins), preterm gestation, low birth weight, high maternal age, and emergency cesarean birth. This study revealed a true increase in incidence of metopic synostosis in Victoria, which could be a result of increased frequency of multiple births, preterm gestation, low birth weight, and high maternal age in the Victorian population from 1982 to 2008. The incidence of other nonsyndromic craniosynostoses, which include sagittal, unicoronal, and multisutural craniosynostoses, however, has remained unchanged.