Fertility, age and men

Men are usually at their peak fertility age in their early to mid-twenties. Research has shown that there is a definite reduction in fertility as men age, however, because this is not as universal as the link between age and fertility in women, this is not as well understood.  

From the age of thirty, a key fertility indicator in males – the level of the hormone testosterone, which is needed for sperm to mature – begins to reduce slowly. 

After the age of forty, a man’s testes start to shrink and soften, and the quality and quantity of the sperm that they produce slowly declines over time.