General · 25 February 2026
Sperm swims best during June and July

Researchers analysed samples from 15,581 men aged 18 to 45 in Denmark and Florida to track fertility changes. The data revealed that swimming ability drops significantly in December and January, even in warmer regions like Florida. Scientists believe these seasonal patterns could help doctors time fertility treatments more effectively for couples trying to conceive. While movement changed, the total count and fluid volume remained the same throughout the year.
Reported by BBC · How we write briefs
