Is There A Male Biological Clock?

Understanding your biological clock, whether you’re a man or a woman, can help you better plan for your future family.

When people talk about the ticking biological clock, they are typically referring to women. After all, common thinking has typically placed the burden of an aging fertility system on women. This isn’t without reason. As you likely already know, women are born with their lifetime supply of eggs, while men continue to create fresh sperm throughout their lifetime. Recent studies are now showing us that while men continue making sperm as the age, the quality of that sperm can decrease. This can lead to serious health risks for both their partner and for their offspring. 

Understanding the male biological clock can help couples better plan their fertility journeys. 

The Risks of the Male Biological Clock

Recent studies have indicated that the male biological clock exists. More importantly, they indicate that the clock needs to be taken seriously. Two studies — one looking at over 7,000 couples going through in-vitro fertilization (IVF) and the second reviewing more than 40 years of medical literature  — have indicated that the male biological clock starts ticking around age 40. At that point, the quality of sperm seems to begin decreasing. 

The impacts of decreased sperm quality begin at the point of conception. According to the studies, men over age 45 take longer to get their partners pregnant. If conception is successful, the man’s partner is significantly more likely to miscarry the older the man is. That’s true even if she is young, healthy, and has no other risk factors. 

The studies further found that if the man is 45 or older, their partner is at greater risk for pregnancy complications including gestational diabetes, preeclampsia and preterm birth. Once the child is born, there is an increased chance of low birth weight, higher incidence of newborn seizures and birth defects such as congenital heart disease and cleft palate. As the child gets older, further complications can come into play. These include a greater likelihood of childhood cancers and psychiatric and cognitive disorders. In particular, there is a significantly higher risk of a child developing schizophrenia if they have an older father. The risk of a child having autism also increases with the age of the father. Studies have shown that the risk of autism starts to increase when the father is 30 years old, plateaus at 40, and increases again at age 50. 

Why Does Sperm Quality Decrease with Age

Unfortunately, scientists don’t know the answer yet. It’s possible that quality decreases naturally with age. On the other hand, it’s possible that the changes in quality are caused by lifestyle and environmental factors. No matter the cause, there are some steps that men can take to improve their sperm quality. These include not drinking excessively, smoking, or using drugs. That won’t eliminate the male biological clock, but it can improve your overall sperm health. 


These studies shouldn’t cause alarm. The male biological clock should not get in the way of a couple’s fertility journey. These studies indicate that couples should start taking the age of the man into account when planning for a family. That may mean that a man hoping to have a family later in life banks their sperm, or perhaps it means reevaluating your fertility timeline. 

If any couples or men specifically are concerned about what the male biological clock may mean for them or for their fertility journey, it is best to consult an expert. The fertility specialists at AFCT can help you better understand your path to a family.