"The production of sperm begins to decrease around 40 years, although it continues into the 80s and 90s. Testosterone production declines after age 30 but very gradually, so resulting physical changes are not evident until later in life"(Jarvis)
idk if you have a background in healthcare but this is my career and what I study 24/7. Men don't have to worry about this kind of stuff like women do, that is why I believe men can wait to marry until their 30s. Women obviously not.
Woman definitely have less fertility years than men.
But it's not the low spern count that's the only concern for older men, it's also the sperm quality, which does decrease with age after around 40. There are ways to increase sperm count but not sperm quality.
Miscarriages are not always the result of a woman's egg or something in her uterus. Poor sperm quality can also cause miscarriages.
Many women wait longer to have kids, and they usually pair up with men older than them so theres a double whammy of her old eggs and his poor sperm.
Late teens early 20s for women and late teens to early 30s for men is ideal biologically. But for very young men and women it's not ideal economically or even socially. Most girls in their prime fertile years are not interested in starting families, and neither are most men in their age group.
So we see people putting this off and then struggling to get have a child.
