Biochemical Semen Analysis

What is the Biochemical Semen Analysis?

The Biochemical Semen Analysis detects various semen parameters beyond sperm cells. The seminal fluid contains a number of substances secreted by accessory sexual organs, mainly including prostate, seminal vesicles and epididymes. These substances are essential for the proper semen physiology and contribute significantly to the sperm survival within the first minutes (30-60min) inside the vagina. Although the prostate gland produces a great number of substances, its function is effectively evaluated by detecting Zink (Zn) levels within the seminal fluid. A reliable marker to evaluate the function of seminal vesicles is the level of fructose levels, while the epididymal function is effectively evaluated by detecting levels of neutral glucosidase.

When is the Biochemical Semen Analysis done?

It is essential to detect the above substances, when there is suspicion for ejaculatory duct obstruction or agenesis (hereditary disease in which there is absence of the vas deferens).  In addition, the therapist physician may order the above tests, when there is suspicion for accessory gland dysfunction, mainly if the man has a history of recurring or severe infections of the lower urinary and genital tract. Lastly, biochemical seminal parameters should be detected in selected cases of idiopathic (of unknown aetiology) male subfertility.

What preparation is needed for the Biochemical Semen Analysis?

For the proper test conduction, the man has to abstain from ejaculating for 2-7 days. The accessory sexual glands produce increasingly high secretions during sexual arousal. The higher the sexual arousal, the ‘better’ the produced secretions –with regard to both quality and quantity. Thus, obtaining seminal sample after sexual activity will give more reliable results than when taken after masturbation in the laboratory.

Lower Urinary Tract Infections (LUTS), such as orchioepididymitis, seminal vesicle infection and prostatitis, will alter the results; therefore, they have to be first treated before the man undergoing the test. Similarly, invasive procedures of the region, such as removal of the testis (e.g. due to malignancy), testicular biopsy, semen obtained from the epididymis, prostate biopsy etc, also have to be taken into account by the therapist physician.

What is the procedure of the Biochemical Semen Analysis?

The evaluation of semen biochemical parameters is conducted along with the evaluation of sperm cells in the laboratory with the use of special techniques.  Proper sampling is described in detail in the “spermiogram” test. In order for the test results to be reliable, it is significant to collect the entire semen sample. The biochemical sperm elements are mainly determined by the amount of semen ejecting last during ejaculation. 

How are the results of Biochemical Semen Analysis interpreted?

  • Each ejaculation should normally contain  > 2,4 μmol Zinc. Should Zinc values be lower, the test is repeated. If the Zink value in the repetitive test is below 2,4μmol, this indicates prostate dysfunction or  ejaculatory duct obstruction
  • Fructose content in the semen should be over 13μmol/ejaculation. Low fructose levels found in the semen at consecutive measurements, indicate dysfunction or obstruction-agenesis of seminal vesicles.
  • Neutral glucosidase should normally reach levels of > 20mU/ejaculation. Low levels of neutral glucosidase in the semen at repetitive measurements, indicate dysfunction-obstruction of epididymes or obstruction-agenesis of  the vas deferens transferring semen from epididymes to the urethra.

The dysfunction of the above accessory sexual glands may be due to other independent factors, such as androgen deficiency (and mainly of testosterone), undernourishment, vitamin deficiency etc.