Infertility is common. In fact, the World Health Organization reports that 17.5% of the global population is affected by infertility, indicating a major health challenge.

Historically, it was thought that the female partner is implicated in the majority of infertility cases, meaning that, in most circumstances where a couple cannot naturally conceive within one year of trying, there is an issue with the female partner’s fertility. However, very recent research shows that male factors contribute to around 50% of all infertility cases, an increase from previous estimates.

“Despite this, men are still less likely to undergo a fertility evaluation compared with women, which means valuable time can be lost in reaching a diagnosis,” explains Dr Gorgy, Fertility Consultant and Co-director at The Fertility & Gynaecology Academy. “We see in practice that the demand for thorough male fertility testing is increasing, but it is clear that awareness still has some way to go.”

With November putting men’s health in the spotlight thanks to charitable initiative Movember, now is the perfect opportunity to open up conversations around male infertility, and to ask whether it could be a bigger issue than we, as a population, have realised.

Why has the impact of male infertility been underestimated?

For decades, fertility has been framed as a “women’s issue”. The focus has overwhelmingly been on women’s bodies, hormones and reproductive choices. This means that male infertility has often been pushed to the sidelines.

Part of this comes down to stigma. Discussions about sperm quality or testicular health are still seen as taboo, and many men find it difficult to talk openly about fertility challenges. Meanwhile, women have historically borne the brunt of medical testing and treatment, reinforcing the idea that infertility is “their problem to solve”.

Cultural expectations also play a role. In many societies, masculinity is strongly linked to virility, so acknowledging male infertility can feel like a threat to identity. This silence has contributed to a lack of awareness, fewer research initiatives, and slower progress in developing targeted treatments for men.

The result is a gap in understanding, support and solutions. Recognising male infertility as a significant factor is not only crucial for improving outcomes for couples, but also reducing the emotional burden that men themselves often carry in silence.

Common causes of male fertility issues

Male infertility can arise from a wide range of factors, sometimes making diagnosis and treatment complex. Below are some of the most common causes that specialists consider when assessing male fertility.

Sperm production problems

The majority of male fertility issues stem from problems with sperm production. These include:

• Low sperm count (oligozoospermia): When the number of sperm in semen is lower than normal, the chances of fertilising an egg naturally are reduced.
• No sperm (azoospermia): A condition where semen contains no sperm at all, which may be due to blockages, genetic conditions or testicular failure.
• Poor sperm mobility: Sperm may be present in normal numbers but unable to swim effectively, making it difficult to reach and fertilise the egg.
• Abnormal sperm morphology: Sperm with irregular shapes or structures may struggle to penetrate the egg.
• Genetic factors: Certain genetic conditions, such as Klinefelter syndrome or microdeletions of the Y chromosome, can impair sperm development or function.

Sperm transport issues

Even when sperm are produced normally, problems with how they travel can prevent conception.

• Varicocele: Enlarged veins in the scrotum can affect sperm quality and production.
• Blocked or absent tubes: Obstructions in the ducts that carry sperm, or a congenital absence of the vas deferens, can prevent sperm from being ejaculated.

Other medical conditions

A number of health conditions can also affect male fertility:

• Infections: Certain Sexually Transmitted Infections (STIs) or other infections can damage sperm or block their passage.
• Testicular injury or trauma: Damage to the testicles can impair sperm production.
• Undescended testicles: If not corrected in childhood, this can cause long-term problems with fertility.
• Hormonal imbalances: Issues with hormones produced by the pituitary gland, thyroid or testes may interfere with sperm production.
• Cancer treatment: Chemotherapy, radiotherapy and surgery can all have significant effects on fertility.
• Ejaculation issues: Conditions such as retrograde ejaculation, where semen enters the bladder instead of exiting through the penis, can prevent sperm reaching the egg.