Causes of Male Infertility
By Dr. Kate Dudek
When a couple seek help for infertility it is a common misconception that the female partner will be responsible for the issue. It is true that there are a wide range of conditions, both medical and environmental, that can impede a female’s ability to fall pregnant. However, in up to 50% of suspected infertility cases the male is also involved. In fact, 30% of the time the problem will be male-specific. The good news is that many male-based problems can be easily diagnosed and treated, without the need to resort to challenging, invasive and costly assisted reproductive techniques (ART). The less good news is that there remains a social stigma with regards to male infertility and, that for as long as men refuse to acknowledge that the problem might lie with them, women will continue to undergo unnecessary procedures and infertility rates will not improve.
So, what are the major causes of infertility in males?
Abnormal sperm production is the largest contributor to male infertility. Low sperm count, or low sperm quality is thought to be involved in up to 90% of cases. Azoospermia occurs when semen analysis identifies no sperm cells. This can be non-obstructive, which is more common, or obstructive. Most cases of non-obstructive azoospermia occur due to testicular dysfunction, which usually results from developmental abnormalities, genetic mutations, trauma or tumour. The obstructive form is less common, affecting 15-20% of men with azoospermia. This occurs when there is obstruction of part of the male reproductive tract, usually the epididymis, the vas deferens or the ejaculatory duct. Other sperm disorders include low numbers (oligospermia), irregularly shaped sperm and sperm that moves the wrong way.
Alternative forms of testicular dysfunction include hypogonadism, which causes a disruption in the synthesis of male-specific hormones, called androgens; and cryptorchidism, a congenital abnormality of the male genitalia, more commonly known as undescended testes. Maldescended testes are normally treated during early childhood; however, do have a strong association with impaired semen in adulthood.
Genetic defects and chromosomal abnormalities are also implemented in male infertility. Of particular concern is the fact that men who have abnormal sperm have a greater chance of passing on genetic mutations and faulty DNA to their offspring, who may then suffer from fertility problems of their own.
40% of infertile men will have varicoceles, which are enlarged veins in the scrotum. They are particularly prevalent in men who have abnormal semen. They usually first appear during puberty and if severe might be treated with ligation using microscopic surgery (varicocelectomy).
Ejaculation disorders are another cause of infertility. These include:
- Anejaculation. Absence of ejaculation; a complete lack of semen emission into the urethra.
- Delayed ejaculation. Abnormal stimulation of the erect penis is required. Difficulty reaching orgasm.
- Retrograde ejaculation. Semen passes backwards into the bladder.
These disorders occur in response to medications, psychological issues, nerve problems, dysfunction of the nervous system, or, in the case of retrograde ejaculation, bladder neck incompetence.
Anti-sperm antibodies may impair fertility. However, they are thought to play a greater role in female infertility, impeding the entry of sperm into the fallopian tube.
The environment, prior or current drug use (pharmaceutical or recreational) and a history of cancer (particularly those that affect the male reproductive organs) can also impair fertility. All of these factors highlight the need for a comprehensive medical evaluation during initial investigative diagnosis. A major challenge remains because in up to 40% of infertility cases, no definitive cause will be identified. This is termed idiopathic male infertility.
The wide range of factors that can have a detrimental effect on male fertility highlights how important it is for couples to face any issues that they have conceiving together. Despite this, figures suggest that when couples first seek help for infertility, a male evaluation will not be performed in at least 18% of cases.
- Katz, D J, et al. “Male Infertility - The Other Side of the Equation.” Australian Family Physician, vol. 46, no. 9, Sept. 2017, pp. 641–646.
- Jungwirth A, et al. European Association of Urology (EAU) guidelines on male infertility. Arnhem, The Netherlands: European Association of Urology, 2015. Available at https://uroweb.org/wp-content/uploads/17-Male-Infertility_LR1.pdf [Accessed 31 March 2019].
- “What Is Male Infertility?” Urology Care Foundation, www.urologyhealth.org/urologic-conditions/male-infertility.