For many men, finding out they’re infertile can be tough. Feelings of guilt, anxiety and embarrassment are common and can be amplified when there’s no clear explanation for infertility, and nothing you can control or change about it. And a specific cause can be found in fewer than 25% of Australian men who use in vitro fertilisation (IVF). So, if you’re one of the many men who’ve been told they have unexplained male infertility (also referred to as idiopathic infertility) here’s what you need to know about the diagnosis, the potential causes and what additional testing and treatment are available, and why there’s still plenty of hope for you when it comes to creating a family.
Firstly, what is male infertility?
Infertility is typically defined as the inability of a couple to conceive a pregnancy after 12 months or more of regular, unprotected sex. It’s estimated that a male factor is involved in about 40% of all infertility cases. A man’s infertility can stem from issues with sperm production (causing poor quality, low count or poor movement), blockages in their reproductive tract, certain health conditions and behaviours that might be changed like smoking, poor diet and carrying extra weight. But for most men, there’s no clear cause.
What is unexplained male infertility, and how common is it?
As the name suggests, unexplained male infertility is a broad term used when standard testing can’t identify a specific cause. Your semen analysis is normal, there are no major red flags in your medical history or physical examination and other testing have come back fine. We don’t have data about how common unexplained male infertility is in our general population, but we do have good information from couples going through fertility treatment. The latest Assisted Reproductive Technology in Australia and New Zealand (ANZARD) report shows that of all the IVF treatments in Australia and New Zealand in which male infertility is involved, 76.6% of the time it is unexplained.
How is unexplained male infertility diagnosed?
Diagnosing unexplained male infertility is a process of elimination.
Your doctor will ask about your health and history
First, your doctor will discuss your medical history, ask about past experiences of injury or infection, whether you’re on any medication and your family history. There is a range of medical conditions that impact male fertility, that you may or may not know you have. Working with your doctor to identify and manage them can improve your overall health and your chances of conception.
If sexually transmitted infections (STIs) such as chlamydia or gonorrhea are left untreated, they can damage the reproductive organs and cause infertility. You can have an STI without showing any symptoms, so if you haven’t had a screening recently, your doctor can organise one. Most STIs can be quickly and easily treated.
Your doctor will also discuss behaviours that might affect your fertility, like your drinking habits, exercise routine, diet, drug use, whether you smoke or you’re exposed to certain toxins in the workplace. You can find more information on male preconception health here.
Then they’ll do a physical examination
In your appointment with your doctor, they’ll do a physical examination to look and feel for any abnormalities that could cause infertility like small testicles (which can indicate Klinefelter syndrome) or a varicocele.
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You’ll do a semen analysis
Your GP will then refer you to have a semen analysis. This involves examination of your semen under a microscope to determine the number of sperm, their size and shape and their movement. But it can’t tell us how sperm will function. You’ll usually provide a sample at a pathology laboratory, or it can be done at home and taken to a lab within 30 minutes. If your first semen analysis is abnormal, you’ll do another one around six or more weeks later.
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You might need a blood test
If the results of your semen analysis are abnormal, you’ve got small testicles or symptoms of low testosterone, you will be sent for a blood test to measure your hormone levels and other indicators of overall health.
After an evaluation by your doctor, you should be further assessed by a specialist in male reproduction, like an endocrinologist, urologist or obstetrician/gynaecologist.
If these tests fail to identify a cause, you’ll get a diagnosis of unexplained male infertility. This is naturally a scary diagnosis to receive, but unexplained infertility does not mean the end of your ability to produce a child, and there are further testing and treatment options available.
Most couples with unexplained infertility conceive in the next one to two years if they continue trying but that doesn’t mean you should put off speaking with fertility specialists, especially if your partner is 35 years or older.
What might cause unexplained male infertility
It’s likely that you’ll never find out the reason why you’re infertile. But when there are no clear anatomical, hormonal, genetic or infectious reasons for your inability to conceive with your partner, here are some of the factors that could be at play.
Problems with sperm function
Semen analysis measures are set by the World Health Organization but none of these factors can truly indicate how sperm will function. Sperm might appear normal in count and quality, but there can be small defects in how they function that affect fertility that don’t show up in testing.
Problems with fertilisation
There’s a lot going on behind the scenes when it comes to fertilising an egg. The sperm needs to reach the egg, attach to it and successfully fuse with it. If something goes wrong in any one of those steps, fertilisation might not happen.
Health behaviours
We know there are things you can do to improve male fertility like quitting smoking, eating a nutritious diet, maintaining a healthy weight and limiting alcohol consumption. Endocrine-disrupting chemicals and environmental pollutants — like pesticides, industrial chemicals, BPA and phthalates — can interfere with hormone production and function, potentially affecting sperm quality and fertility. While they don’t always lead to clear-cut diagnoses, ongoing exposure to endocrine-disrupting chemicals is increasingly recognised as a possible contributor to unexplained infertility in men.
Antisperm antibody formation
Antisperm antibodies are immune system proteins that mistakenly target and attack your own sperm, treating them as foreign invaders. These antibodies can interfere with sperm movement, prevent sperm from penetrating an egg or cause sperm to clump together — making it harder to achieve fertilisation. They may form after injury to the testicles, infection or surgery (like vasectomy or reversal), but sometimes no clear trigger is found.
Sperm DNA fragmentation
Sperm carry half the genetic material needed to make a baby, so if the DNA inside them is damaged, it can affect the sperm’s ability to fertilise an egg or can lead to early miscarriage — even if the sperm look totally fine under the microscope. This kind of damage isn’t usually picked up in a regular fertility check, but it’s more common in men who are older, smoke, or have been exposed to environmental toxins. Sperm DNA fragmentation testing might be recommended to you.
How is unexplained male infertility treated?
There are currently no treatments for unexplained male infertility, but there is a fertility treatment called intracytoplasmic sperm injection (ICSI) can help you and your partner conceive.
Intracytoplasmic sperm injection (ICSI) is a type of IVF technique, but instead of mixing thousands of sperm with an egg and hoping one gets in (like in traditional IVF), ICSI involves injecting a single healthy-looking sperm directly into an egg using very precise lab equipment. This can help overcome issues like problems with the sperm’s ability to attach to or penetrate the egg.
“One of the words that chaffs me a little bit is that IVF is a treatment for male infertility,” says Healthy Male’s Medical Director, andrologist Prof Rob McLachlan AM. “It is not a treatment [for him]. His partner, she gets the drugs, she has eggs collected, she has the embryos transferred. He gives a sample and goes home. We can’t fix [unexplained male infertility] but we can get around it by doing ICSI. But philosophically it’s not a treatment, It’s a spectacular bypass procedure.”
Recent data from the ANZARD report shows that when ICSI is used, men with male factor infertility — including unexplained cases — have similar chances of having a baby as couples with other infertility diagnoses.
“I look forward to the day, as we start to unpeel the onion of male infertility. What are the causes? What are the pathways? What is exactly going on in there?” says Prof McLachlan. “Then we’ll be able to give guys some treatment that will put them back in the natural fertility game. Until that happens, IVF is the pathway that will get them the family they seek.”
You can listen to more from Prof Rob McLachlan on male infertility on our podcast, Dad Starts Now.
Unexplained male infertility can be an incredibly frustrating and emotionally draining experience for couples. For men, it can bring feelings of isolation, inadequacy, or even a loss of identity — so it’s important that you feel supported at every stage of the fertility journey, regardless of the outcome. Because infertility can also put pressure on a relationship, open communication and, in some cases, couples counselling can offer valuable emotional support during what is often a difficult and uncertain time.
If you’re struggling, chat with your GP.
