A laboratory examination begins with sperm liquefaction, usually after 15 – 30 minutes. Microscopic sperm examination focuses on its quantity, motility and morphology. Sperm quality changes over time, thus additional examination is usually performed after 4 or more weeks.
World Health Organization (WHO) values
World health organization establishes new recommended values for a semen analysis test.
Recommended values for an ejaculate examination (semen analysis) are periodically checked and updated by the WHO and come from results of fertile men. In spring of 2010, the WHO issued the fifth edition of the “World Health Organization Laboratory Manual for Examination and Processing of Human Semen”, which brought many changes, mainly in the area of result evaluation.
Semen analysis examination does not mean placing the tested patient into either fertile or infertile category. Even men with a low semen quality can have a baby. The WHO parameters represent a global tool for evaluation of men fertility – they provide standardized and comparable values.
The amount of sperm usually does not affect fertility. The amount of sperm cells present in the ejaculate is the main factor.
Normal pH is slightly basic, acidic pH value kills sperm cells.
Is determined under microscope in squares. Then, the total sperm concentration in the ejaculate can be calculated.
The ability to move. The WHO divides motility as follows:
- a: Progressive motility (PR) = spermatozoa moving actively, either linearly or in a large circle, regardless of speed
- b: Non-progressive motility (NP) = all other patterns of motility with an absence of progression, e.g., swimming in small circles, the flagellar force hardly displacing the head, or when only a flagellar beat can be observed.
- c: Immotility (IM) = no movement
Sperm shape is considered a very important fertility affecting factor. Sperm cells (spermatozoon or spermatium) consist of three parts: head, mid (connecting) piece and a tail.
The head contains nucleus with genetic information and is surrounded by an acrosome, which contains enzymes for penetrating the female egg. The mid piece has many mitochondria, which produce ATP for energy support, allowing forward movement. The tail propels the sperm cell forward by lashing motion.
Sperm antibodies can also affect fertility. These antibodies decrease sperm motility. They are examined by immunological tests. Tests for IgA and IgG immunoglobulins is performed on a fresh sperm sample, either by the “immunobead test” (IBT) or by the “mixed antiglobulin reaction” (MAR).
Agglutination means the clumping of motile sperm cells (spermatozoa) by their heads, mid sections, tails or mixed (head to tail, etc.). Agglutination can indicate a possible immunologic cause of infertility but it does not prove that this is the exact cause.
Leucocytes assessment in the semen
Leucocytes assessment in the semen – if the sperm contains a large quantity of leukocytes, it can indicate an existing infection or inflammation. More than a million leukocytes in 1 ml of semen is considered significant.
A semen analysis using a very high resolution microscope (MSOME) or an examination of the sperm – a hyaluronic acid linkage is specialized examination performed in reproductive medicine, which allows for better selection of the most suitable spermatozoa for fertilization. There are also other tests that can examine genetic integrity of sperm cells (Sperm Chromatin Structure Assay, SCSA) and identify how many sperm cells are genetically modified. The PCT test – an examination of the interaction between the sperm and the cervical mucus-is very common.
Which factors affect semen analysis results?
Semen analysis is affected by stress, psychological problems or even by the worries of the test results. Unhealthy lifestyle, such as smoking and obesity, also affect results. Other factors are overtraining, excessive alcohol consumption and fever-inducing illnesses. Spermatogenesis occurs under lower temperature levels, so frequent hot water bathing, sauna and warm and tight underwear are not recommended. Vitamins E and C are beneficial for spermatogenesis.