With regards to male fertility, until what age can a man have healthy children?

FOREVER: The sperm are continually formed. As opposed to the female eggs which are present from birth and continue to be release ever time you ovulate. Thus as long as the man produces sperm , he can father healthy children.

50+: Many men remain fertile well into their 50s and 60s. However, the risk for conceiving a child with some kinds of uncommon genetic disorders increases when the man is more than age 50.