Varicocele and Fertility

A man in his mid-thirties comes in holding an ultrasound report. He and his partner have been trying for a baby for two years. She has been through everything — cycle tracking, hormone tests, her tubes checked — and all of it came back normal. Only later did anyone think to check him. His semen analysis showed a low count. The scan found a varicocele. He looks at the report and says: “So it’s me, then.”

Relief and blame, in the same breath. Relief that there is finally an answer. Blame that the answer seems to be him.

If you have landed here, you may be somewhere in that same sentence. Perhaps you have just been told you have a varicocele and you are trying to work out what it means for your chances of becoming a father. Perhaps you are further along, weighing up whether to treat it. Either way, the question underneath is usually the same: is this why — and can it be fixed?

Here is the honest shape of the answer. A varicocele is one of the few causes of male fertility problems that can actually be corrected. That is genuinely good news, and it is worth holding on to. But correcting a varicocele is not a switch that turns pregnancy on. It improves the conditions; it does not guarantee the outcome. Anyone who promises you more than that is selling a certainty that does not exist.

What follows is how I think about varicoceles and fertility — when they matter, when they do not, what the evidence actually shows, and how I decide who I would treat and who I would leave alone. Some of it is more detail than you may want today. Take what is useful now; the rest will be here when you need it.

What a varicocele is — and why it can affect fertility

A varicocele is a collection of enlarged veins above and around the testicle, a bit like varicose veins in the leg. The valves that should keep blood moving in one direction stop working properly, so blood pools instead of draining away. On examination a larger one can feel like a soft “bag of worms” above the testicle.

The reason this matters for fertility comes down to one thing: heat and stagnation. Sperm production is exquisitely sensitive to temperature — it is the whole reason the testicles sit outside the body in the first place. When blood pools, it warms the testicle and creates what is called oxidative stress: a build-up of reactive molecules that damage developing sperm. Hold on to the phrase oxidative stress — it comes back later, because it is also the key to understanding a test that goes beyond the standard semen analysis.

Does a varicocele cause infertility? The honest answer

Here is the thing that surprises most men. Varicoceles are common — somewhere around 15 in every 100 men have one. If a varicocele automatically meant infertility, that would be a staggering number of men unable to have children, and that is simply not the case. In fact, roughly two-thirds of men with a varicocele are perfectly fertile.

But turn the question around and the picture changes sharply. Among men who are struggling to conceive, a varicocele turns up far more often — in almost one in two. And when a varicocele is genuinely part of the problem, correcting it tends to help: somewhere between six and seven men in ten see their semen quality improve afterwards.

So the honest answer to “does a varicocele cause infertility?” is: not on its own, and not in everyone — but in the right man, at the right grade, it can be a real and correctable factor.

How varicoceles are graded — the two scales, and why both matter

Not all varicoceles are equal, and the grade matters a great deal when deciding whether treatment makes sense. There are two different grading systems, and they measure two different things — which is exactly why confusing them causes so much needless worry. Let me set them out plainly.

The first is the Dubin–Amelar scale, which grades by physical examination — what can be felt and seen. It runs from 1 to 3: grade 1 is felt only when you bear down, grade 2 is felt at rest, and grade 3 is visible through the skin.

The second is the Sarteschi scale, which grades by colour Doppler ultrasound — what the blood is actually doing. It runs from 1 to 5 and describes the pattern of venous reflux: from reflux seen only when you strain (grade 1), through to spontaneous reflux present at rest (grades 4 and 5). One scale tells you what can be felt; the other tells you what is happening to the flow. They are complementary, not rivals — and a proper assessment uses both.

The practical headline that cuts across both: the smallest varicoceles — those picked up only on ultrasound and not felt at all — are called subclinical, and I do not treat these for fertility. It is the ones that can be felt, and that show a meaningful reflux pattern on the scan, that may genuinely matter.

If you are holding a report that says “grade 2”, this is exactly why it is worth asking which scale was used — a grade 2 felt in clinic and a grade 2 on ultrasound are not describing the same thing.

The semen analysis — and why it is not the whole story

The first test in any fertility work-up is a semen analysis. It measures the things you would expect: how many sperm there are (concentration), how well they move (motility), and how normally they are shaped (morphology). For most men with a varicocele affecting fertility, this is where the problem shows up, and it is the main thing I look at when deciding whether to treat.

But here is the part that catches couples out: a semen analysis can come back entirely normal, and a couple can still be struggling to conceive. The standard test counts sperm and watches them swim — it does not look inside them. And sometimes the problem is inside.

Sperm DNA fragmentation: looking beyond the standard test

Sperm DNA fragmentation is a measure of how much breakage there is in the genetic material the sperm is carrying. A sperm can look normal and swim well, yet carry damaged DNA — and that damage can affect fertilisation, early embryo development, and the risk of miscarriage. This is where that earlier phrase comes back: the damage is largely driven by oxidative stress, the same mechanism a varicocele sets up.

This is the part of my practice that goes a little beyond the standard guidelines, so I want to be straight about where the evidence sits. In a man with a clinical varicocele and a normal conventional semen analysis but a high DNA fragmentation result, I think correction can be justified — because the varicocele is plausibly driving the fragmentation, and meta-analyses do show fragmentation improving after repair. But I would describe this as an emerging, evidence-informed position rather than a universal standard of care. A urologist who took a more conservative line here would not be wrong; the evidence is still maturing.

One useful piece of evidence cuts against a tempting shortcut: the grade of a varicocele does not reliably predict how high the DNA fragmentation will be. In other words, you cannot guess fragmentation from the size of the varicocele — it has to be measured. That is precisely why, in the right couple, I measure it rather than assume.

When I would recommend treatment — and when I would not

This is the heart of it. A varicocele being present is not, by itself, a reason to treat it. What I am weighing is whether this varicocele, in this man, is likely to be holding back fertility in a way that correction can change. In practice, I would consider treatment in three situations:

• • Infertility with abnormal semen parameters and a clinical varicocele
• • (Sarteschi 3–5). This is the standard, well-evidenced indication.
• • Infertility with normal semen parameters but high DNA fragmentation
• • , again with a clinical varicocele. This is the emerging indication described above — offered after an honest conversation about what the evidence does and does not show.
• • Typical varicocele pain with a clinical varicocele.
• • Where the grade is low, I would usually start with pelvic floor physiotherapy before considering correction.

Just as important is when I would not treat. I do not treat subclinical varicoceles (Sarteschi 1–2) for fertility, and I would not rush to treat a varicocele found by chance in a man who is fertile and has no symptoms. Knowing when to leave something alone is as much a part of good urology as knowing when to act.

And there is a wider point I want to make here, because it gets lost so easily. A varicocele may be something happening in your body, but fertility is rarely a one-person story. The right decision is made by looking at the whole picture — your situation and your partner’s together. If, for example, time is tight for reasons on your partner’s side, then waiting several months to see whether your semen improves may not be the best use of that time, and it is worth discussing the options with a fertility specialist before deciding. None of that reduces the case for treating a varicocele that genuinely needs it — it simply means the decision belongs to the two of you, not to a test result in isolation.

What treatment involves: subinguinal microsurgery

When I correct a varicocele, I do it by subinguinal microsurgery — a small incision low down, below the level of the groin crease, through which the enlarged veins are tied off while the artery, the lymphatic channels and the vas are carefully preserved. It is done under general anaesthetic, as a day case, so you go home the same day.

Two pieces of equipment make the difference between a good result and a complication. The first is an operating microscope, which magnifies the cord enough to tell the tiny artery and lymphatics apart from the veins. The second is an intraoperative vascular Doppler, which lets me hear and confirm the artery so it can be protected rather than caught. This matters because the two things you most want to avoid — a build-up of fluid around the testicle (hydrocele) and the varicocele coming back — are both far less likely when the lymphatics and veins are properly identified.

The evidence backs this up. With microsurgery, recurrence and hydrocele rates fall to roughly 1–2% and 0–1% respectively — substantially lower than non-microsurgical techniques, where hydrocele alone can occur in anywhere from 3% to nearly 40% of cases. The microscope and the Doppler are not luxuries; they are what makes the operation as low-risk as it is.

What to realistically expect afterwards

The single most important thing to understand is that nothing changes overnight. Sperm take around two and a half months to make — the full production cycle is roughly 74 days — which means the sperm in a sample taken just after surgery were made before anything was corrected. For that reason I check a semen analysis at around three months, and again at six. Most of the improvement that is going to happen tends to show by three months.

And the honest framing, again: improvement in semen quality happens in a majority of men, and pregnancy rates do go up after correction — but a better semen analysis is not the same as a guaranteed pregnancy. Treatment opens a door; it does not walk you through it.

This is also where the couple’s picture matters most. If after a few months the numbers have improved and conception follows naturally, wonderful. If they have not, that information is itself valuable — it lets you and your partner move on to other options, such as assisted conception, without having spent years wondering. Either way, you are making the next decision together, with better information than you had before.

The bottom line

A varicocele is common, and on its own it does not mean you cannot have children. But in a man who is struggling to conceive, with the right grade and the right findings, it can be a real factor — and one of the few that can actually be corrected. The decision to treat rests on the grade (I treat clinical varicoceles, not subclinical ones), on the semen analysis, and sometimes on DNA fragmentation when the standard test looks normal but something still is not right.

Most of all: a varicocele may be happening in your body, but fertility is something you and your partner face together. The best decisions get made looking at both of you, not at one test in isolation — and never under the weight of believing it is simply your fault.

Related reading