Diagnosing Male Infertility
By Dr. Kate Dudek
Infertility, or a failure to conceive after 12 months of having unprotected sexual intercourse, affects approximately 15% of all couples. Much of the focus on infertility has, to date, looked at problems relating to the female reproductive system. However, with male factors thought to be involved in up to 50% of all infertility cases, it is important that, if a problem is suspected, men also undergo comprehensive investigations.
The first step should be undertaking a detailed medical history. Male infertility is not solely due to sperm abnormalities and it is important to also consider the effect of the environment, previous medical conditions and familial history. These can all affect male fertility. At this stage, a physical examination will also be performed to check for structural abnormalities in the penis or testes. The doctor will also look for varicoceles (enlarged veins in the scrotum).
A semen analysis is usually considered the ‘gold standard’ approach for investigating male infertility. It is used to analyse sperm volume, count, concentration and movement, and will also identify irregularly shaped sperm and whether there is an abnormally high number of white blood cells (leukocytes).
The reference values, according to the World Health Organisation are:
Sperm concentration ≥15million/mL
Total sperm count ≥39 million
Total motility ≥40%
Progressive motility ≥32%
Normal morphology ≥4%
If results are abnormal, a second sample will be taken as high variability is common. Even if results remain outside of the reference values, absolute infertility is rare and, with time, many couples do conceive.
Ideally a robust biomarker of male infertility will be identified in the semen (or serum). Assays to detect various proteins thought to be implicated are currently under development. At one time it was thought that anti-sperm antibodies might serve this purpose, however, their presence is now considered to be only loosely correlated with pregnancy rates (they may play a far more important role in determining female infertility, as they have been found in the follicular fluid and the blood).
The benefit of semen analysis should not be understated; however, it will not identify all male-related infertility factors and often additional testing is required.
Blood samples may be taken to measure the levels of circulating hormones. Low levels can be indicative of particular problems, for example, low testosterone can be a sign of testicular failure; low testosterone, low follicle stimulating hormone and low luteinising hormone in combination, indicates a problem with the hypothalamic-pituitary axis (hypogonadotropic hypogonadism). If this axis is disrupted it can hinder the release of sex hormones from the testes.
Other tests include transrectal ultrasound and/or MRI to identify ejaculatory duct obstruction, and post-ejaculatory urinalysis to check for retrograde ejaculation. Whilst testicular biopsies used to be widely used as a diagnostic tool for male infertility, the limited information they provide, in addition to the invasive nature of the technique, means they are no longer used as standard.
With such a wide spectrum of tests available, if a couple are struggling to conceive and the problem is thought to be with the male, identifying the issue, and hopefully resolving it, should be possible.
- Bieniek, J M, et al. “Seminal Biomarkers for the Evaluation of Male Infertility.” Asian Journal of Andrology, vol. 18, no. 3, 2016, pp. 426–433., doi:10.4103/1008-682X.175781.
- Chiu, W W, and L W Chamley. “Clinical Associations and Mechanisms of Action of Antisperm Antibodies.” Fertility and Sterility, vol. 82, no. 3, Sept. 2004, pp. 529–535, doi:10.1016/j.fertnstert.2003.09.084.
- 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.
- “What Is Male Infertility?” Urology Care Foundation, www.urologyhealth.org/urologic-conditions/male-infertility.