How many times have you read, been told, or watched someone lecture about what happens to us ladies as we age? Aside from the greying of our hair, the sagging of our bottoms, and the wrinkling of our skin, we can look forward to the withering of our ovaries. Sounds like fun! And while we women are used to shouldering all of the blame, men and advanced paternal age play a pretty sizable role in the fertility equation. Just because guys make sperm almost all of their life doesn’t mean that they should make a baby with this sperm. Here’s why.
Let’s start with a bit of basic biology…the process of sperm production in men is called spermatogenesis. Unlike oogenesis (the production of eggs), which occurs ONLY when you are a fetus inside of your mother’s womb (remember, a girl is born with ALL of the eggs she will ever make), spermatogenesis is like the Energizer Bunny—it keeps on ticking.
However, just like any device that is running on batteries that have seen their better days, over time, things start to go awry. Things stop moving, start sounding funny, and become unable to perform their duties. The situation is really not all that different with sperm. As guys age, their sperm-production battery (a.k.a. spermatogenesis) starts to become more error prone. We see more breaks in DNA (the genetic material that is passed down to your future lineage) and a higher frequency of mutations within the DNA. These mistakes translate into abnormal sperm, which translates into abnormal embryos and infertility. Additionally, as men age, their semen volume decreases, sperm motility decreases, and the percent of normal sperm decreases—D-Day is upon them.
The length of time it takes a couple when the male partner is older to conceive is longer than the time it takes a couple when the male partner is younger. The line in the “age” sand is debatable and usually set anywhere between 45 and 50. The same delay in conception appears to hold true even when doing IVF; older sperm will likely set you back (how much time is not clear).
And while the sperm may be slacking, there are also data to suggest that paternal age has a significant impact on how often a couple with an older partner not only has sex but also on sexual function. Studies show that older men have sex less often due to decreased sexual desire and diminished sexual function. Less sex is going to equal less chance of conceiving, no matter how good the sperm he still has.
Research has also shown us that advanced paternal age (again, think 45 or 50 years old) has an impact on specific genetic and medical conditions. These include autosomal dominant disorders (achondroplasia, Apert’s syndrome, Marfan syndrome, etc.) as well as schizophrenia, autism/autism spectrum disorder, and certain congenital anomalies. How or why these diseases or errors happen is not super clear. So far, scientists think the money is on a reduced amount of antioxidant enzymes hanging around in the semen. Think of these enzymes as the police; they are responsible for cleaning or stopping abnormalities. Just like a city without a good police department, the fewer enzymes, the more potential problems for the sperm and the resultant embryo.
Newer evidence also suggests that children born from older dads may have a SLIGHTLY higher chance of childhood cancers (specifically, leukemia and brain/nervous system tumors). Given these risks, most of us OB/GYNs will recommend chatting with a genetics counselor either before or in the very early stages of pregnancy. They can help break down even the most complex of issues and set the stage for what can happen when the curtain goes up.
Fertility is a two-way street. While we have let the guys off the hook when it comes to age in the past, we now know that paternal age does matter. It can most definitely play a role in infertility and abnormal pregnancies. Sperm, like their egg counterparts, seem also to be on the hunt for the fountain of youth. This is important to remember when looking for the cause of infertility.
And although we joked about it, this process is way stressful, and therefore, there is no need to blame, to point fingers, or to look for fault. While we want to find cause, we don’t want to ascribe blame. That train has left the station. It’s time to move together towards our destination.