Interested in starting a new family or expanding an existing one? Now is the time to strike, according to new fertility research. Men’s sperm count and strength is at its peak in winter and early spring, scientists report.
To reach these conclusions, the researchers sampled semen from 6,455 men over a three year period.
During the colder months, they found, sperm swim faster and are generally at their healthiest, FitPregnancy reports. As the weather warms, however, the sperms’ spontaneous, independent movements slow. The faster the sperm can swim, the more likely it is that one of them will successfully reach the egg at the end of the finish line.
Men also produce more sperm during in this window. A man who turns out 70 million sperm per milliliter of semen in February will produce 68 million come June. While that’s still a lot of sperm, those 2 million could make the difference between good news or trying again next month.
More from Smithsonian.com: