Understanding fertility in men
Conceiving a healthy baby depends on a number of factors, including healthy sperm. In fact, male infertility is the second biggest issue after a woman’s age so it’s important to understand how the male reproductive system works.
Male factor infertility affects around half of all infertile couples, the good news is that the most common causes of male infertility are easily diagnosed, and most can also be treated.
Sperm production starts in the testes, where the hormone testosterone is also produced. An average of 100 million sperm are produced every day in healthy young men. After sperm is produced, it will need to travel along a long channel system starting at the epididymis, where they mature along the way, before exiting via the ductal structures called vas deferens and then out the urethra as part of the ejaculate. The entire process of sperm production and maturation takes just under 3 months. Any serious illness may affect sperm production for up to three months.
A sperm consists of the head, tail and mid-piece sections. To successfully fertilise an egg, the sperm will need to be able to move its tail (motility) to propel itself through cervical mucus to then travel through the uterus and fallopian tube to reach the egg. It will also need to be normally shaped in order to penetrate the outer shell of the egg to deliver its genetic package contained in the head.
There are four key components necessary to achieve satisfactory sperm production and a pregnancy:
- Normal hormonal stimulation from the pituitary gland
- Normal sperm production in the tubules of the testes
- An unobstructed sperm pathway
- Effective natural sperm delivery
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Is there a biological clock ticking for men, too? Dr Frank Quinn, fertility specialist with IVFAustralia, discusses male fertility and whether getting older can impact sperm quality. Watch via our Fertile Minds YouTube Channel.
Does age affect male fertility?
Women are often told to have babies early, while it's assumed that most men can reproduce well into their 60s and 70s.
But is there a biological clock ticking for men too? You'll find out in today's Fertile Minds video.
Welcome to Fertile Minds. I'm Dr. Frank Quinn, a fertility specialist here at IVFAustralia. My experience lies in reproductive endocrinology and infertility and I've had the privilege of helping men and women become parents over the last 25 years in Australia.
Does the age in fact affect male fertility? To give you some background, a normal semen analysis result would show a sperm count of at least 15 million sperm per mil, with at least a third of those showing fast, progressive, forward movement. In a semen analysis, we look for the following features to define sperm health:
- Firstly, the semen volume, the average volume of semen produced in the ejaculate.
- Sperm concentration, the number of sperm per mil in the semen sample.
- Motility and morphology, the movement of the sperm and their size and their shape.
- And also, the total sperm number in the ejaculate.
- We also look at vitality, the percentage of living healthy sperm in the semen sample.
Age and male fertility. While men in fact can reproduce well into their 60s, ageing sperm unfortunately does have an effect on the health of the offspring. We've seen increasing conditions like autism, attention-deficit hyperactivity disorder and schizophrenia. The risk of this is 10 times higher for men in their 60s, as opposed to men in their 20s. Other risks include genetic diseases, such as achondroplasia or dwarfism or Apert syndrome, characterised by skeletal abnormalities. When men reach the age of 45, they tend to have higher rates of fertility complications in their sperm volume, motility and morphology, all of them declining. There is also an increased likelihood of damage or breaks into the sperm DNA that may have a negative effect on their fertility.
You may be wondering if the female partner is younger than 35, should you as the male partner over 40 be concerned about your age. Research has revealed significantly lower clinical pregnancy rates in men above the age of 40 whose female partners were less than 35. We also know that in those pregnancies, unfortunately, there can be a higher instance of first trimester miscarriage and those women, in pregnancy, have a higher instance of premature labor and babies born small for their gestational age. So unfortunately, as men do get older, it can affect the quality of the sperm and the health and outcome of the subsequent pregnancy.
So what fertility options are available to men? We certainly know about the fertility options for women. Women concerned about their age may opt to undergo an IVF cycle and through a process of hormonal injections, have multiple eggs mature, collected and frozen for a later date. But what about the men?
Men for a long time have frozen sperm but usually, this has been in an oncological setting. So men diagnosed with cancer, typically testicular cancer, may opt to have sperm frozen before they go through treatment that may affect their fertility at a later date. But there's a growing evidence of research coming together, suggesting that as men age, so does the quality of their sperm decline. And likewise, men perhaps should consider as they get older, do they freeze their sperm to preserve their fertility as women have done in the past?
So an interesting fact is that men who have no sperm in their ejaculate may be concerned as to whether they could have sperm to freeze. And in actual fact, some men would have sperm production occurring within the testicles. Through a surgical procedure, oftentimes that occurs under a general anesthetic, we place a needle into the testicle and aspirate sperm that can be later frozen and used as part of an IVF treatment cycle.
Unfortunately, some men will have several semen analyses that come back with suboptimal parameters. And a common question that's asked is what lifestyle factors can they address to try and improve the quality of their sperm.
The first of these, without a doubt, is to stop smoking. We know smoking can affect the DNA within the sperm. It doesn't cause mutations or breaks or damages the DNA, it does in a more subtle way, it affects the way that the DNA that is packaged within the sperm. And that's associated with a higher incidence of miscarriages and also childhood cancers for those children at a later date. So smoking definitely is one thing that will dramatically affect the quality of the sperm and is highly recommended to discontinue. We also know that alcohol in a high concentration will affect the quality of the sperm and the ability of their partner to conceive.
Other lifestyle factors also include anabolic steroids. In a growing world of Instagram and Facebook, when people want to look good, more men are resorting to synthetic ways to improve their looks. But unfortunately, anabolic steroids have a significant detrimental effect on the quality and the amount of sperm. Some men will actually become azoospermic or have no sperm from taking anabolic steroids. And even when they stopped them, a large percentage of them, their sperm does not recover.
Other lifestyle factors include weight and exercise. We know that men that are overweight unfortunately have increased fat around their thighs and lower abdomen, which affects the temperature within the scrotum and the testes. The reason that the scrotum is outside the body is to keep it a degree cooler than core temperature, to optimise spermatogenesis. So weight also affects sperm quality, concentration and motility and the men who are trying to start a family and struggling, then exercising and to optimise their weight is strongly encouraged.
So I hope you found this video helpful. I always recommend, if you're concerned about your age or your fertility or the quality of your sperm, to make an appointment with a fertility specialist because we're always happy to help. If you would like to see more videos speaking on all things fertility, make sure you hit the subscribe button (for our channel).
*All opinions expressed on the Fertile Minds YouTube Channel belong to the individual doctors, scientists and specialists, not the Virtus Health group.