Even a large seasonal variation in the length of the daylight period does not affect sperm characteristics. And no significant seasonal variation in the DNA fragmentation index (DFI) was observed.
This according to a new thesis from Gunilla Malm, doctoral student at the Department of Translational Medicine and MD at the health care centre Örestadsklinikens vårdcentral in Malmö.
The study included approximately 200 men in Norway (Oslo and Tromsø).
Photo: Ellen Malm