Oligospermia is a medical condition characterized by a low sperm count in semen. It is a common finding in male infertility and can be diagnosed based on one low count in a semen analysis performed on two occasions. For many decades, sperm concentrations of less than 20 million sperm/ml were considered low or oligospermic, but recently, the WHO established a lower reference point of less than 15 million sperm/ml, consistent with the 5th percentile for fertile men. Sperm concentrations fluctuate daily, and oligospermia may be temporary or permanent.
There are many causes of oligospermia, including pre-testicular causes, testicular causes, and post-testicular causes. Pre-testicular factors refer to conditions that impede adequate support of the testes and include situations of poor hormonal support and poor general health, including hypogonadism due to various causes, drugs, alcohol, smoking, and strenuous riding. Testicular factors refer to conditions that affect the testes directly, such as genetic abnormalities, infections, and trauma. Post-testicular factors refer to conditions that affect the transport of sperm from the testes to the urethra, such as obstruction of the vas deferens.
In most cases of oligospermia, including its idiopathic form, there is no direct medical or surgical intervention agreed to be effective. Empirically, many medical approaches have been tried, including clomiphene citrate, tamoxifen, HMG, FSH, HCG, testosterone, Vitamin E, Vitamin C, anti-oxidants, carnitine, acetyl-L-carnitine, zinc, and high-protein diets. In a number of pilot studies, some positive results have been obtained, and clomiphene citrate has been used with modest success.
The treatment of oligospermia depends on the cause of the condition. For instance, surgery may be needed to treat a varicocele or blocked sperm. In some cases, stopping medications or behaviors that are contributing to low sperm levels may increase sperm count. Men with oligospermia may also be able to increase the chances of conception by having sex more frequently, tracking ovulation, and making lifestyle changes such as quitting smoking and reducing alcohol consumption.