Male Infertility: Semen Analysis, Causes and Treatment Options

Infertility is a couple's issue

Infertility is the absence of pregnancy after one year of regular unprotected intercourse (six months if the woman is 35 or over). In about half of couples, a male factor is present, alone or together with female factors. Delaying the male partner's assessment until the woman's tests are complete can delay diagnosis and treatment.

The gynaecologist assesses the couple as a whole; when male findings emerge, detailed examination, further tests and surgical treatments are planned together with urology/andrology specialists.

Semen analysis

Semen analysis is the first and key test. It measures sperm count, motility and shape (morphology), as well as semen volume and other features.

How to give a sample

• 2-7 days of sexual abstinence (no ejaculation) is recommended beforehand.
• The sample is collected by masturbation into the sterile container provided. Lubricants and standard condoms should not be used as they can harm sperm.
• The whole ejaculate should be collected; the first portion is the richest in sperm. Any loss should be reported to the laboratory.
• Ideally the sample is given at the laboratory. If collected at home, it should be kept at body temperature and delivered within about an hour.
• A high fever in the previous two to three months can temporarily affect results and should be mentioned.

Understanding the results

The 2021 WHO laboratory manual gives the lower limits (5th centile) of values in men whose partners conceived within 12 months:

• Semen volume: 1.4 mL
• Sperm concentration: 16 million per mL
• Total sperm number: 39 million per ejaculate
• Total motility: 42%
• Progressive motility: 30%
• Vitality: 54%
• Normal forms: 4%

These values do not draw a sharp line between "normal" and "abnormal". Partners of men below these limits can conceive, and being above them does not mean pregnancy will occur. Results are interpreted in the context of the couple.

Common terms: low count is oligozoospermia, low motility asthenozoospermia, few normal forms teratozoospermia, and no sperm in the ejaculate azoospermia.

Semen values vary considerably over time in the same man, so decisions are not based on a single abnormal result; the test is usually repeated after a few weeks to three months, or sooner if azoospermia or a very low count is found.

Causes of male infertility

Several factors often coexist, and in some men no clear cause is found despite full assessment (idiopathic infertility).

Varicocele

A varicocele is an enlargement of the veins draining the testis. It is found in about 15% of men overall and about 35-40% of men presenting with infertility. It can impair sperm production by raising testicular temperature and oxidative stress. Not every varicocele needs treatment; treatment is considered in infertile men with a palpable varicocele and abnormal semen parameters.

Hormonal causes

Sperm production is regulated by FSH and LH from the pituitary gland. Insufficient pituitary hormones (hypogonadotropic hypogonadism), high prolactin and thyroid disorders can reduce sperm production. These causes are less common but important to find because they can be treated with medication.

Genetic causes

Genetic causes are more common in men with azoospermia or a very low count. The main ones are Klinefelter syndrome (47,XXY), Y chromosome microdeletions and CFTR gene variants (see below).

Obstruction

If sperm production is normal but the ducts carrying sperm (epididymis, vas deferens) are blocked, there is no sperm in the semen (obstructive azoospermia). Previous infections, hernia surgery, vasectomy and congenital absence of the vas deferens are the main causes.

Infections

Mumps orchitis after puberty, epididymitis and sexually transmitted infections such as chlamydia and gonorrhoea can affect sperm production or transport.

Lifestyle and environment

• Smoking, excess alcohol and recreational drugs
• Excess weight and obesity
• Frequent, prolonged heat exposure of the testes: saunas, very hot baths, a laptop on the lap, long periods of sitting
• Occupational chemicals such as pesticides, heavy metals and solvents
• Older paternal age

Medications and anabolic steroids

External testosterone and anabolic steroids used for sport suppress the brain's signal to the testes and can severely reduce or stop sperm production; recovery after stopping can take months. Chemotherapy and radiotherapy, some drugs such as sulfasalazine and long-term opioid use can also affect sperm production. All medications and supplements should be reported to the doctor.

Other causes

A history of undescended testes, testicular torsion or injury, testicular cancer and its treatment, retrograde ejaculation (for example with diabetes) and erectile or ejaculatory problems can also cause infertility.

Assessment with urology/andrology

When semen analysis is abnormal or there are risk factors, the male partner's detailed assessment is coordinated with urology/andrology specialists. The gynaecologist brings these findings together with the woman's assessment to build a shared plan for the couple. Assessment may include:

• Detailed history: past illnesses and surgery, medications, occupation, habits and sexual function
• Physical examination: testicular size and consistency, varicocele and presence of the vas deferens
• Hormone tests: FSH, LH, total testosterone and prolactin when needed
• Scrotal ultrasound and Doppler; further imaging if obstruction is suspected
• Post-ejaculation urine test if retrograde ejaculation is suspected
• Sperm DNA fragmentation testing in selected cases, such as recurrent pregnancy loss or unexplained IVF failure
• Genetic tests when indicated

Genetic assessment and counselling

Guidelines recommend genetic testing for men with azoospermia or a very low count (thresholds vary between guidelines, usually below 1-5 million per mL). These tests help explain the cause, guide treatment options and assess the chance of passing a condition on.

• Karyotype: the most common finding is Klinefelter syndrome (47,XXY). Most men with Klinefelter syndrome have no sperm in the ejaculate, but sperm can be found in testicular tissue in some. Structural changes such as balanced translocations can be linked to low counts and pregnancy loss.
• Y chromosome microdeletions: small losses in the AZF regions (AZFa, AZFb, AZFc) responsible for sperm production. The region involved helps predict the chance of finding sperm: very low with complete AZFa or AZFb deletions, while sperm may be found with AZFc deletions. These deletions are passed to sons conceived with ICSI.
• CFTR testing: congenital absence of the vas deferens (CBAVD) is usually linked to variants in the cystic fibrosis gene (CFTR). The female partner should also be tested for carrier status.

When a genetic cause is found, genetic counselling is recommended to explain what the results mean for the couple, the chance of transmission and, where appropriate, options such as preimplantation genetic testing (PGT).

Treatment options

Treatment is planned for the couple together, according to the cause, semen parameters and female factors such as age and ovarian reserve.

Lifestyle changes

Stopping smoking, reducing alcohol, reaching a healthy weight, regular exercise and avoiding excess heat are recommended. Sperm production takes about two and a half to three months, so the effect on semen parameters appears only after this period. Evidence on the effect of antioxidant and vitamin supplements on pregnancy is limited.

Treating the cause

• Surgical or interventional treatment of varicocele in suitable men (by urology)
• Gonadotropin (hCG and FSH) treatment in hypogonadotropic hypogonadism
• Treatment of high prolactin and thyroid disorders
• Treatment of infections
• Stopping anabolic steroids or testosterone; testosterone suppresses sperm production and is not used to treat infertility in men wishing to father a child
• Surgical repair of some obstructions

Intrauterine insemination (IUI)

For mild male factor, motile sperm prepared in the laboratory are placed into the uterus with a thin catheter at ovulation. The woman's tubes must be open.

IVF and ICSI

When the count or motility is markedly low, or sperm is retrieved surgically, ICSI is used: a single sperm is injected into each egg, allowing fertilisation with very few sperm.

Surgical sperm retrieval (TESE and micro-TESE)

In azoospermia, sperm can be retrieved directly from the testis or epididymis by a urologist. In obstructive azoospermia, sperm can usually be obtained by needle or a small tissue sample (TESA, PESA, TESE). In non-obstructive azoospermia, where production is impaired, micro-TESE is preferred, searching under the microscope for small areas that produce sperm. Retrieved sperm is used for ICSI and can be frozen. Timing with the IVF cycle is planned jointly by the two teams.

Sperm freezing

Before treatments that may affect fertility, such as chemotherapy, radiotherapy or testicular surgery, sperm can be frozen for future use.

When should you see a doctor?

• No pregnancy after one year of regular intercourse (six months if the woman is 35 or over), with both partners assessed together
• A history of undescended testes, testicular surgery or injury, or mumps orchitis
• Cancer treatment planned or received
• Swelling, pain, small testes or a varicocele
• Erectile, ejaculatory or libido problems
• Use of testosterone or anabolic steroids

Frequently Asked Questions

The information on this website is for general information only and does not replace a medical consultation.

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