Seasonal Patterns of Birth in Patients with Glioblastoma

Seasonal distribution of birth rates was only recently described in patients with high‐grade gliomas. We analyzed 501 cases from the database of a Regional Cancer Center in Bavaria to assess annual periodicity in the birth dates of glioma patients. Prior to analysis, the number of births per month was normalized [number of births×100,000/total number of births in Germany] to obtain birth rates per month. The approximation of the time series data by a one‐year cosine model found that the glioblastoma birth rate exhibits a statistically significant annual variation, with the peak rate in January. Vitamin intake, infections, and other as‐yet‐unknown factors and exposures during pre‐ and perinatal early life may contribute to the seasonality of birth rate in patients with brain tumors.