New research from the United States has found that men produce better sperm in the spring and autumn, although the reasons for this remain unclear. A big study analysed sperm samples from more than 29,000 men over a period of 17 years, and found that there were more moving sperm in the spring and more normally-shaped sperm in the autumn.
The researchers, from Icahn School of Medicine in Mount Sinai in New York presented their research at the annual conference of the American Society for Reproductive Medicine in Denver. They have suggested that the milder weather might have something to do with this as the sperm will stay cool but men are likely to be more physically active and that they may be less likely to be drinking too much alcohol than in the summer or at Christmas. As it takes three months to produce sperm, it is not entirely clear what the causes may be – but the researchers make it clear that more research is needed to be able to confirm that their findings would have an impact on the chances of a successful pregnancy at different times of year.