Most men are fertile until old age, but time brings a set of physical changes that affect many men’s ability to father children. It is possible for men to have kids late into their lives, but once most men reach 40 or so, the likelihood of them fathering a child starts to decrease. Here’s more helpful information about the correlation between age and male fertility.
How age affects male fertility
For starters, we know that at this age many men’s sexual functioning begins to change. As they get older, men tend to have a more difficult time getting and keeping erections, and they often need a longer resting time in between orgasms. This doesn’t mean that they enjoy sex any less. It’s just different; less frequent, and less easy to start and complete.
Oh, and don’t forget the sperm – they change too. More sperm are made that are abnormally shaped. Sperm motility declines and overall semen concentration tends to drop, which can render men who already had a low sperm count nearly unable to fertilize an egg. The rates of sperm cells being damaged, known as DNA fragmentation, also rises with age.
All of these factors lead to less frequent sexual intercourse, less successful sperm-and-egg encounters, and a higher prevalence of miscarriages and certain conditions (autism, ADHD, behavior problems, to name a few) among children born to older fathers.
The data isn’t clear, and there have been plenty of healthy babies born to older fathers. But ultimately it’s very likely that the older men get, the more complications they and their partners face when trying to have a child.