Women are born with a finite number of eggs and the egg quality and quantity decreases with age until it’s depleted.  Hence the woman’s ticking biological clocks is the pressure to have children once they hit a certain age. But men produce sperm throughout their lifetime unless due to disease or some damage.  One man has even fathered a child at the age of 96!  Do men have a biological clock?  Does age affect men’s fertility?  The answer is that aging does affect male fertility although its decline is slower than in women.  Increasing male age is associated with increased time to pregnancy and decreased pregnancy rates.

At what age does fertility decline in men?

A decline in fertility in a male is not as pronounced as in a female.  Male fertility generally decreases after the age of 40. (1)

How does aging affect male fertility?

  1. Semen volume– There have been many studies about the relationship between men’s age and semen volume and most of the studies have found that there is a decrease in semen volume as men grow older.  One such study found that semen volumes peaked between ages of 30 to 35 years and were significantly less in men who were more than 55 years old. (2)
  2. Sperm motility– which is how well the sperm can swim is also affected with age.  Many studies found a decrease in motility with increasing age. (3)
  3. Sperm morphology- which is the size and shape of the sperm is more subjective and its interpretive results can vary from lab to lab.  Normal sperm has an oval head with a long tail whereas abnormal sperm have defects in the head or tail. Again most of the evidence found a decline in normal sperm morphology with age. (3)
  4. There are also higher levels of DNA damage in the sperm with increasing age in turn leading to genetic defects in the offspring like Down Syndrome, autism, and schizophrenia.  This could also cause decreased fertility, increased stillbirth or chances of miscarriage. (4) 
  5. Hormonal factors- Declining testosterone may cause decline in libido, erectile dysfunction, and difficulty achieving ejaculation. The level of testosterone does appear to influence sexual function.  High levels of testosterone in the testicles are needed for sperm production.  As men age, testosterone levels decrease.
  6. Medical issues and medications- Medical illnesses like blood pressure, diabetes and issues with the prostate could develop later on in life for which you might need to take medications.  These illnesses or medications could in turn affect fertility.

So, the ability of sperm to fertilize an egg decreases with paternal age.  Even by going through certain assisted reproductive technologies like IVF, pregnancy rates decreased as the age of the men increased. (5)  There could also be a rise in complications in the mother like placenta previa, hypertension, preterm labor, miscarriage, decreased birth weight amongst other things if the father is older.  Invitro fertilization (IVF) is a procedure where a woman’s egg is retrieved, and placed together with many sperm in a laboratory setting in the hopes that one of the sperm will fertilize the egg.  The resulting embryo is then transferred back into the woman’s uterus for implantation hopefully leading to a pregnancy.  Intracytoplasmic sperm injection (ICSI) is an additional procedure done with IVF where an individual sperm is selected by the embryologist and it is injected directly into the egg.  It is usually used to treat those with severe male infertility or for other medical reasons.  A study has found that when using ICSI together with IVF, the obstacles due to a man’s age could be overcome if the woman’s oocyte or egg is young and healthy. (6)

What can you do?

You cannot grow younger but there are some things you can do to improve sperm health and improve the odds of having a baby.  You can lead a healthy lifestyle like eating a well balanced diet rich in fruits and vegetables, stop smoking, stop drinking excessively, maintain a healthy weight, do regular exercise, avoid hot tubs, and minimize stress.  Increasing sexual frequency could also improve sperm health. There are still a lot of unknown factors about the effect of male aging on fertility and further research needs to be done to better understand the impact of a man’s age on fertility.  If you are struggling with infertility or have questions or concerns about this topic, feel free to contact the experts at Xenith Advanced Fertility Centre.