Seasonal Variations in Cerebral Palsy Births.

INTRODUCTION: Previous studies of cerebral palsy (CP) suggest that it seasonal variations in the incidence of CP. The purpose of this paper was to compare seasonal variations in the incidence of cerebral palsy (CP) in Podlaskie Province, Poland, between 1990-1999 (study 2005) and 2000-2014 (study 2017) in a retrospective case-controlled study.

MATERIALS AND METHODS: Data were obtained from the hospital database. We compared CP births between January 1, 1990, and December 31, 1999, n = 212 (116 boys, 96 girls) and January 1, 2000, and December 31, 2014, n = 205 (114 boys, 91 girls). We used Cosinor analysis to examine the seasonality of CP births.

RESULTS: The highest number of CP births occurred in spring and the lowest in winter, with intermediate values in summer and autumn. This seasonal pattern was significant for spring vs. winter. The peaks in the numbers of CP births occurred in May and August; the lowest numbers of CP births occurred in February, December, and November. In the 2017 study, we observed a slight increase in spastic tetraplegia and a decrease in mixed CP. No significant corrections between mean temperature and Apgar score, low birth weight, and asphyxia were found.

CONCLUSIONS: Our study confirmed the existence of seasonal patterns for CP births.