Sperm quality is highest in the summer and lowest in the winter, according to a new study. Researchers from the UK, Canada and Denmark analysed semen samples from 15,581 men in Denmark and Florida, all aged between 18 and 45. Their findings show that sperm motility - the ability of sperm to swim effectively - was consistently highest in June and July for both parts of the world. Understanding these seasonal patterns could improve fertility treatments, by optimising the timing of treatment and fertility testing to provide better guidance to couples trying to conceive. The study, published in the journal Reproductive Biology and Endocrinology, suggests that sperm's motility levels remain consistent across different climates, instead changing with the seasons. Levels were lowest in December and January, even though Florida remains warm all year round.…