Human semen quality may rise and fall in seasonal variation, with the best quality being produced in the winter and spring.
Research suggests that semen produced during that time has a greater concentration of sperm of which a higher percentage are fast moving and appear normal when looked at under a microscope.
Researchers took semen samples from 6,477 men who had been referred with their partner to a fertility clinic in Israel. Men who had sperm counts in the normal range averaged 71 million sperm per millilitre in spring, which fell to a low of 64 million in autumn. Although total sperm motility was greatest during the summer months, the percentage of fast-moving sperm, thought to increase the chances of fertilisation, was highest in winter.
In men with lower than normal sperm concentration seasonal variation was less marked. The highest percentage of sperm with normal morphology was in the spring, and a slight trend towards greater motility was also observed during this time. However neither the concentration of sperm or the percentage of fast-moving sperm altered significantly between seasons. Read full article.
