Infertility
Half of it is male factor — and the workup usually starts with the woman
What it is
Infertility is conventionally defined as failure to conceive after 12 months of regular unprotected intercourse — or after 6 months if the female partner is over 35, because time matters more then. It affects roughly one in seven couples. Its causes are distributed far more evenly between partners than almost anybody expects: MALE FACTOR CONTRIBUTES TO ROUGHLY HALF OF CASES, either alone or alongside a female factor. The remainder is made up of ovulatory disorders (PCOS being the commonest), tubal disease, endometriosis, uterine factors, and a substantial category — around a quarter — that remains genuinely unexplained.
Why it matters
Because the investigation of infertility is one of the most asymmetric processes in medicine, and the asymmetry is not justified by the biology. Male factor accounts for about half of infertility. A semen analysis is cheap, non-invasive, quick, and can be done in the first week. Yet in practice the workup frequently begins — and sometimes ends — with invasive investigation of the woman, while the man is tested late or not at all. Fixing that is free, and it is the single highest-value change available in this area. The second thing that matters is TIME: female fertility declines with age, and the decline accelerates after 35. Every month spent on a supplement, an app, or a wait-and-see is a month that cannot be recovered.
What BioSignal knows about treating this
What works for Infertility
BioSignal’s clinical summary, most important first.
- TEST BOTH PARTNERS, AND TEST THEM AT THE SAME TIME — male factor is roughly half of infertility and a semen analysis is quick, cheap and non-invasive. Any pathway that investigates the woman for months before testing the man is a badly designed pathway, and it is a common one
- DO NOT WAIT IF THERE IS A REASON NOT TO — 12 months is a guide for couples with no known problem. Over 36, irregular cycles, known endometriosis, or previous pelvic infection all mean seek help sooner. Time is the resource that cannot be replaced
- Stop anabolic steroids and exogenous testosterone — a common and frequently reversible cause of a zero sperm count, and one many men have never been warned about
- Folic acid before conception — this is not about fertility, it is about preventing neural tube defects, and it must be started BEFORE pregnancy to work
- Stop smoking, moderate alcohol, and address weight in either direction — genuine, evidence-based effects on fertility in both partners
- Ovulation induction where ovulation is the problem — letrozole is more effective than clomiphene in PCOS, which is a change many people have not caught up with
- Treat the identified cause — endometriosis, tubal disease, submucosal fibroids, thyroid disease each have specific management
- IUI, IVF and ICSI as indicated — genuinely effective, and success is strongly age-dependent in a way clinic marketing rarely makes plain
- SUPPLEMENTS, honestly: folic acid is essential and non-negotiable. Beyond that, CoQ10, DHEA and 'egg quality' formulations are widely sold and the evidence is weak to insufficient. They are not a substitute for a diagnosis, and the months spent on them are months of the one thing you cannot get back
Signal Records relevant to this condition
Interventions and contributing factors — some of these records describe a cause rather than a cure. The rating shown is BioSignal’s confidence in that Signal Record, not a claim about how well it treats this condition. Open any of them for the full evidence.
- Testosterone TherapyModerate confidence
Effective for genuine hypogonadism; no established benefit at normal levels. Suppresses fertility. Ask why testosterone is low before treating the number.
- Coenzyme Q10 (CoQ10)Limited evidence
Doesn't fix statin muscle aches — the trials tested that and it failed. The real open question is heart failure, where one randomised trial reported fewer deaths.
- DHEALimited evidence
The anti-ageing claim was tested and failed. The vaginal formulation is an approved, effective medicine. Route and population decide everything.
- Vitamin DHigh confidence
Effective for deficiency and for bone health in at-risk groups. For broad disease prevention in adults who are already replete, the largest trials are null — and confidence in that null is high. Routine testing of healthy adults is not supported.
- AlcoholHigh confidence
A Group 1 carcinogen with dose-dependent harms. The heart-protection belief does not survive the methods designed to test it. Cutting back helps, even without quitting.
New to this? Read these first
How this usually unfolds
- Recognize risk factors
- Get diagnosed
- Track key biomarkers
- Lifestyle first
- Evidence-based treatment
- Long-term monitoring
Who is at risk
- Female age — the dominant single factor, with decline accelerating after 35 and sharply after 40
- Male factor: low sperm count, poor motility, abnormal morphology, varicocele, prior infection, testicular injury
- Ovulatory disorders — PCOS is the commonest
- Endometriosis
- Tubal damage — from pelvic inflammatory disease, chlamydia, or previous surgery
- Obesity, and also being significantly underweight — both in either partner
- Smoking — in either partner
- Alcohol, and heavy cannabis use
- Anabolic steroid and testosterone use in men — a common, under-recognised and often reversible cause of azoospermia
How it's diagnosed
The assessment should proceed IN PARALLEL, not in sequence, and this is the single most important structural point. Semen analysis for the male partner, and assessment of ovulation and tubal patency for the female partner, should be initiated together. Ovulation is confirmed with a mid-luteal progesterone; ovarian reserve may be assessed with AMH or antral follicle count; tubal patency with HyCoSy or hysterosalpingography. Referral should not wait 12 months where there is a known problem — irregular cycles, known endometriosis, previous pelvic infection, prior chemotherapy, or a female partner over 36.
Key biomarkers
Lifestyle
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Frequently asked questions
Should my partner get tested too?
Yes — first, and at the same time as you, not after months of investigating you. Male factor contributes to roughly HALF of all infertility, either on its own or alongside a female factor. A semen analysis is cheap, quick, non-invasive and can be done immediately. Despite this, the standard pathway in many places begins with invasive investigation of the woman and gets to the man late, or not at all. If you are being worked up for infertility and your male partner has not had a semen analysis, that is the question to ask at the next appointment, and it is not an unreasonable one.
What does my AMH result mean?
Less than you have probably been told, and this is one of the most mis-sold tests in consumer health. AMH is a measure of ovarian RESERVE — roughly, how many eggs are left — and it is genuinely useful for one thing: predicting how you will respond to the drugs used in IVF. It is NOT a test of your chance of conceiving naturally. A low AMH in someone who is ovulating regularly does not mean you cannot get pregnant this month, and a reassuring AMH does not mean you have time. It says nothing about egg QUALITY, which is driven by age. 'Fertility MOT' packages built around AMH are selling a number that does not answer the question people are buying it to answer, and they cause a lot of unnecessary distress.
Does taking testosterone affect fertility?
Yes — profoundly, and a great many men are never told. Exogenous testosterone, whether prescribed as TRT or taken as an anabolic steroid, suppresses the body's own signal to the testes and can drive sperm production to ZERO. It functions, in effect, as a male contraceptive. This is one of the more common and more reversible causes of male infertility, and it is routinely missed because nobody asks. If you are trying to conceive and you are taking testosterone in any form, this needs to be raised with a clinician before anything else is investigated. Recovery is usual after stopping, but it can take many months.
Do fertility supplements work?
Folic acid does, and it is essential — but it is not a fertility supplement. It prevents neural tube defects in the developing baby, and it has to be taken BEFORE you conceive to do that. Beyond folic acid, the honest answer is disappointing: CoQ10, DHEA, inositol and the various 'egg quality' formulations are heavily marketed and the human evidence ranges from weak to insufficient. They are not dangerous, and they are not a diagnosis. The real cost is not the money — it is the months. If you are over 35, or if something is actually wrong, the time spent hoping a supplement will work is time that cannot be recovered.
How long should we try before getting help?
The 12-month rule is for couples with no known problem and a female partner under 36. Seek help SOONER — around six months, or straight away — if the female partner is over 36; if cycles are irregular or absent; if there is known endometriosis, PCOS, or previous pelvic infection or surgery; if there is a known male factor or a history of testicular problems; or if either partner has had chemotherapy. Waiting is not neutral. Female fertility declines with age and the decline accelerates after 35, so the cost of a year of waiting is not the same at 29 as it is at 38.
Evidence summary
Infertility affects approximately one in seven couples. Male factor contributes to roughly half of cases, either alone or in combination with a female factor, and semen analysis is a low-cost, non-invasive first-line investigation that is frequently deferred. Female age is the dominant determinant of fecundity, with a well-characterised decline accelerating after 35. AMH and antral follicle count measure ovarian reserve and predict response to controlled ovarian stimulation; they do NOT reliably predict natural conception, and their marketing to consumers as general 'fertility tests' is not supported by the evidence. Exogenous testosterone and anabolic steroid use suppress spermatogenesis and are a common, reversible cause of male infertility. Letrozole is superior to clomiphene for ovulation induction in PCOS. Smoking, obesity, low body weight and heavy alcohol use reduce fertility in both partners. Preconception folic acid prevents neural tube defects and must precede conception. IVF and ICSI are effective, with success strongly age-dependent. Evidence for CoQ10, DHEA and other 'egg quality' supplements is weak to insufficient, and BioSignal does not have grounds to recommend them.
References & sources
- NICE CG156 — Fertility problems: assessment and treatment
- ESHRE and ASRM guidance on the investigation of the infertile couple
- WHO laboratory manual for the examination and processing of human semen
- Randomized trials of letrozole versus clomiphene citrate for ovulation induction in PCOS
- Studies of anti-Müllerian hormone as a predictor of natural conception versus IVF response
Educational information — not medical advice
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