Once in every woman's life, they're bound to tell a man that they're "biological clock is ticking". Mainly, a woman says this when she's getting close to 40 years of age; because that's the near age when menopause starts. By biological clock, I mean that she's running out of time to have a baby. For some women, this isn't always a bad thing, but with others, it means they're losing their fertility (or firtleness). Generally this biological clock thing is only related to women. Surprisingly, it actually applies to men as well.
Women are born with as many eggs as they'll ever have - about a million. That number steadily diminishes, and "the best eggs are ovulated first," Behr says. The ones that remain - after age 35 or so, on average - are vulnerable to toxins, radiation and other insults that may degrade their quality and viability.
A Biological Clock for Dads Too - Yahoo! News
This basically explains why women have the problem of having a biological clock. Even before hitting puberty, women/girls are already going through eggs. It's not really even apparent to them until they start their menstrual cycles. So by the time they reach their mid 30's-early 40's, their supply of eggs is running up. Basically their clock is ticking, and they can't do anything about it.
By contrast, men make new sperm about every 90 days, Behr says, so the logic has been that there should not be that much difference between a young man's sperm and an old man's. Indeed, men as old as 94 have been known to father children.
A Biological Clock for Dads Too - Yahoo! News
Even with the saying that the sperm of a young man and an old man shouldn't be that different, it's proven that older men are more likely to pass on disease to their offspring. It's obvious that it's harder to have children at an older age. Miscarriages, disease, even death can occur from having a pregnancy at a late age.
There are many possible explanations for the decline in male fertility, from a decrease in the number of sperm and their motility to lower testosterone levels to the effects of other age-related diseases like diabetes, which is associated with erectile dysfunction and lower levels of testosterone. But researchers think that genetic factors may be behind the link between paternal age and a child's risk of bipolar disorder and psychiatric disorders like autism and schizophrenia, whose origins are increasingly being attributed to DNA. Although sperm may be no more than 90 days old, the cells that make sperm may be subject to increasing DNA mutations as men age, affecting the quality of the sperm they produce.
A Biological Clock for Dads Too - Yahoo! News
Women may not be fertile at an age anymore, but at least they're not spreading disease through DNA, or having kids at 94 years old-which is just weird.
