Share Photo: (Photo : Photo by Deon Black from Pexels) Men believe they will be fertile for a long, long time. However, the truth is much more complicated. A growing body of evidence suggests that age has a significant impact on men's fertility. Indeed, the fertility of men does not stop as abruptly as the fertility of women. The testis can still make testosterone and sperm cells from the male hormone, allowing certain men to have children in their 90s. It does not mean, however, that male fertility does not affect age. One study showed that conception was 30 percent lower for men over the age of 40 than for men under 30 after adjustment to women's age.