Infertility is considered a disease of the reproductive system that is found after a period of 12 months of unsuccessful pregnancy attempts, in which the couple had sexual intercourse without the use of any contraceptive method. Currently, it is estimated that infertility affects 10% to 20% of couples of reproductive age, regardless of their ethnic or social origins.
In 30% of couples who are unable to conceive, the man is solely responsible for the cause of infertility, with female causes associated with male causes occurring in 20% of cases. Therefore, it can be said that male problems are present in about 50% of infertile couples. Because male problems are so common, proper investigation of the infertile male is essential.
The spermogram is the main evaluation test, being in most cases the first to be requested in the investigation of infertile men. About 80% of men with difficulty getting their wives pregnant have low sperm concentration associated with decreased motility and/or altered morphology.
The spermogram is a highly variable test, for the same individual, on different collection days, so it is advisable to obtain two semen analyzes before offering an opinion on the patient’s condition. A period of abstinence of 2 or 3 days must be respected. Changes in the period of abstinence may invalidate comparisons between analyses. The exam should be collected in the laboratory or reproduction clinic through masturbation and collected in a special glass or plastic container with a wide opening, avoiding the loss of material.
The analysis methodology and distribution percentiles are described by the World Health Organization, in its 5th edition, revised in 2010, and are represented in the table below.
|parameters||(5th percentile – 95% CI)|
|Seminal volume (ml)||1.5 (1.4-1.7)|
|Total sperm count (10 6 / ejaculate)||39 (33-46)|
|Sperm concentration (10 6 /ml)||15 (12-16)|
|total motility||40 (38-42)|
|Progressive motility (%)||32 (31-34)|
|Morphology (normal forms, %)||4 (3-4)|
Biological proof of male infertility is only possible in cases of complete absence of sperm or complete absence of sperm motility. The interpretation of the values of the seminal parameters defined by the WHO must be carried out with great care and attention. Reference values do not represent the average concentration of sperm in the general population or the minimum values required for spontaneous pregnancy. In addition, patients with seminal parameters outside the normal reference range may be able to get their partners pregnant. Therefore, the sperm analysis should not be seen as a test of male fertility.
Therefore, caution should be exercised in the use of sperm analysis for the diagnosis of male infertility. Men presenting the parameters within the suggested reference as normal, even so, may have difficulty getting their partners pregnant. Although the spermogram is intended to help sexologists in Delhi estimate the relative fertility of a given individual, seminal parameters definitely do not allow the definitive classification of patients as fertile or infertile.