The male biological clock
Actor Charlie Chaplin fathered children at 70 and 73. Media magnate Rupert Murdoch became dad to his youngest two when he was well into his 70s. But does this mean men don’t need to worry about any use-by date on their sperm?
This has been a voraciously argued topic with several studies coming out in recent years showing that while men can continue to produce sperm throughout their life, the quality and quantity both start to drop off as they get into their more senior years.
Start before 40
A 2005 study of 1938 couples in France found that:
- a woman younger than 30 was 25% less likely to conceive if her male partner was 40 or older than if he was of similar age.
- a woman 35 to 37 was 50% less likely to conceive if her partner was aged 40 or over.
Besides declining fertility, other studies have linked a man’s age of when he fathers a child to higher rates of health problems and learning difficulties in kids.
Research has found that children born to fathers 45 or older are more likely to have poor social skills, and that children born to men 55 and older are more likely to have bipolar disorder than those born to men 20 to 24 years of age at the time of conception. Studies have also found links between older fathers and schizophrenia and autism.
And it seems that most fertility specialists agree that as a man ages, his sperm can show more signs of DNA damage.
Some sperm facts
The thing about sperm is that they’re freshly made on a regular basis – which is one reason why the male biological clock doesn’t tick as loudly, or grind to a halt as finitely, as the female’s.
Whereas women are born with all their eggs and no new ones are made (hence, when a woman is 40 years old, so are her eggs), men are making a whole new batch of sperm of every 70 or so days.
Men produce up to 30 billion sperm about every four weeks. They are made in the seminiferous tubules within each testicle, then mature as they migrate through the epididymis, a network of tubes at the back of each testicle that collect and store immature sperm.
Do sperm have a use-by date?
Many men will continue to produce sperm throughout their life although their count will certainly drop as they age. But even though sperm are being made all the time, the body making them is getting older and, possibly, less healthy.
Obesity, diabetes, poor diet and unhealthy lifestyles all play an important role in the health of sperm. Cancer treatments are also known to impact on the health of sperm and a man’s overall fertility.
This article was written by Fiona Baker for Kidspot, New Zealand's best conception and pregnancy resource.