2023 Author: Anita Thornton | [email protected]. Last modified: 2023-05-22 03:30
It was in 1677 that Antonie van Leeuwenhoek, a fabric merchant who spent his free time making microscopes, first observed sperm in a semen sample.
He describes his discovery as “a multitude of animals so small that a million is about the size of a grain of sand, with a thin translucent tail that ripples” (Figure 1). At that time, many theories had already been put forward about the development of a new human being. Some thought that the sperm emitted a kind of vapor that stimulated the formation of an embryo in the woman's body or that the man transferred already formed mini-humans into the body of his partner, who in fact only played an incubator role for the future baby. Some of these concepts even date back to antiquity, where the poet and philosopher Titus Lucretius Carus had already tried to provide explanations for the production of sperm and the role of the "seeds" of man and woman in human reproduction!
Figure 1. Sperm (rabbit and/or dog) drawn by Antonie van Leeuwenhoek, circa 1678.
Despite these discoveries, heIt took more than 200 years before the investigation of male infertility through semen analysis was proposed. It was in the 1930s that the standardization of semen analysis began to be introduced routinely in laboratories. In 1936, a doctor by the name of Hotchkiss proposed a method of standardizing semen analysis in the laboratory by issuing reference values for different sperm parameters: pH, volume, viscosity as well as the general appearance of the semen and concentration., motility, vitality and sperm morphology. This method is still widely accepted and used today, although the reference values have since been revised.
Over time, semen analysis has become an essential analysis in the evaluation of male infertility and is generally the first test prescribed to couples who consult in assisted reproduction. Nowadays, a complete male fertility check-up generally includes a physical examination of the reproductive organs (testicular volume, presence of the vas deferens and absence of varicocele) and a spermogram, an analysis of the main sperm parameters (Table 1). The new reference values for these sperm parameters, determined by the World He alth Organization (WHO), were last revised in 2010. However, it is important to note that men with sperm parameters considered abnormal do not are not necessarily infertile; data fromspermogram should be interpreted in combination with other clinical information. In some assisted reproduction centers, such as Fertilys, the spermogram also includes from the outset the analysis of the integrity of the DNA of the spermatozoa, a parameter which, if abnormal, can compromise the fertilization potential of the latter. This decision by Fertilys to immediately integrate the analysis of the integrity of sperm DNA into the routine spermogram, unique in Quebec, has in fact been recently strengthened by a scientific study published in 2019 which confirms that a fragmentation Elevated sperm DNA is associated with a significant reduction in the probability of pregnancy and birth in intrauterine inseminations.
Table 1. Reference values of sperm parameters determined by WHO 2010 in the 5th edition of the laboratory manual for the examination and preparation of human sperm.
| Parameter | Reference value |
|---|---|
| pH | ≧ 7.2 |
| Volume (mL) | 1, 5 |
| Sperm concentration (106/mL) | 15 |
| Total sperm count (106/ejaculate) | 39 |
| Total mobility (%) | 40 |
| Vitality (%) | 58 |
| Morphology (%) | 4 |
In the presence of an abnormal spermogram, other complementary tests may also be prescribed, such as:
- Blood tests to assess levels of certain hormones (FSH, LH, testosterone, prolactin, TSH, and estradiol).
- Genetic tests to examine the chromosomes (karyotype) and/or to identify Y chromosome microdeletions.
- A testicular and scrotal ultrasound.
- A urine test for sperm.
Men are generally less inclined to consult a doctor for problems related to their reproductive he alth, yet one in two fertility problems is of male origin. The participation of the man is however essential to determine the medical processes most likely to improve the chances of pregnancy. With the new advances in the field of male infertility and assisted reproduction, a diagnosis of infertility can be easily obtained through the analyzes described above. This diagnosis, however, should not be seen as a sign of weakness or impotence, but rather as a well-defined medical condition that can be treated in the vast majority of cases!
