Zabeth Basic knowledge of age related changes in men’s sperm goes back nearly 60 years,

Does A Male Biological Clock Exist?
The answer would appear to be yes! Men often take for granted the fact that they can create sperm for their entire lives. There is no timeframe after which men are unable produce sperm in the same way that women go through menopause. Many men assume that because they make sperm all of their lives that they have the same ability to conceive healthy children at 50+ as they were able to do in their 20s and 30s. Science is mounting that that is in fact NOT the case.
Much has been made of the female biological clock; however, the male biological clock often goes ignored. Basic knowledge of age related changes in men’s sperm goes back nearly 60 years, HOWEVER SOCIETY CHOOSES TO IGNORE (OR FLAT OUT DENY) THIS INFORMATION. Here are some things to consider:
Age can make it harder for men to produce quality sperm that's able to conceive a child. The risk of birth defects also increases with the age of the father. For example, men over 40 are nearly six times more likely to father an autistic child than men under 30. Schizophrenia may also be more prevalent in children fathered by older men.
The cells that create a man's sperm divide roughly once every 16 days. By the time a man is 50, that division has occurred more than 800 times. Those cells determine the genetic code that will be in the sperm- and every time they divide, there's a chance that the genetic code will be altered. With every alteration comes a greater chance of genetic deterioration that could open the door to birth defects.
It takes only 24 cell divisions in a woman's body to produce her lifetime supply of eggs, and those divisions occur before the woman is even born. That may provide more genetic stability for eggs than for sperm.
With age a man's body can produce less testosterone. And that in turn can reduce sperm count and the quality of sperm available- including its ability to trigger a pregnancy.
Sexual performance can also decline with age.
Bottom line: Fertility rules! Nature doesn’t make mistakes. Men and women both can’t delay child rearing forever or until it’s the “perfect” time. There’s no such thing as the “perfect time,” by the way. If you want to have a family, you don’t have your whole life to wait things out.