Clinical Interpretation of Semen Analysis

Abstract

Semen analysis is a fundamental step in the evaluation of the male fertility potential. However, fertility is a “couple-concept” implying the importance of the partner’s fertility status. In fact, a part from extreme conditions (e.g., azoospermia, necrozoospermia, total immotile spermatozoa, etc.) sperm parameters are not fully predictive for natural pregnancy. Semen analysis is divided into macroscopic and microscopic evaluation, and it provides information on the efficiency of spermatogenesis and the integrity of post-testicular structures. Based on the WHO reference values, it is possible to identify alterations of semen parameters, which may derive from many different etiologies. It is essential that the laboratory performs the analysis according to the current WHO guidelines and participate at an external quality control (EQC) program. The clinical interpretation of these alterations is the focus of this chapter.

Low human sperm motility coexists with sperm nuclear DNA damage and oxidative stress in semen

“…Taking account of the 5th centile values provided by 6th edition of the WHO manual, Björndahl et al 5 . and Krausz and Farnetani 4 three groups of men were distinguished: 71 men with < 30% sperm cells with progressive motility (< 5th centile) (experimental group). This group was classified as a group of men with low sperm motility, that is, with asthenozoospermia.…”

“…Although the 6th edition of the WHO manual abandons the terms of basic seminological categories (normo-, astheno-, oligo-and teratozoospermia) 3 some andrological experts currently use these concepts to properly interpret basic sperm variables. 4 Additionally, Björndahl et al 5 in the most recent commentary to the WHO's manual allow the use of clinical categories of semen, provided that the studied groups, methods used, and limit values are defined.…”

“…(2) endocrine abnormalities, (3) chromosomal abnormalities (diploidy, disomy, nulisomy, and microdelations of somatic and sex chromosomes in sperm cells), (4) epigenetic abnormalities (e.g., microRNA alterations), (5) specific mutations of genes (e.g., sperm mitochondria-, annulus-and flagella-related genes), (6) infections/inflammations in the urogenital system leading to leukocytospermia and consequently to oxidative stress (OS) in semen, (7) varicocele usually coexisting with OS, and (8) prolonged sexual abstinence, lifestyle and pollutants, which are also connected with OS. 4,[6][7][8][9][10][11][12][13][14][15][16][17][18] Particularly noteworthy are those factors that lead to the generation of pathological amounts of reactive oxygen species (ROS) at impaired antioxidant capacity. As a result, OS occurs.…”

“…It is suggested that men who had < 30% sperm cells with progressive motility may need a certain diagnostic or therapeutic intervention. Although the 6th edition of the WHO manual abandons the terms of basic seminological categories (normo‐, astheno‐, oligo‐ and teratozoospermia) 3 some andrological experts currently use these concepts to properly interpret basic sperm variables 4 . Additionally, Björndahl et al 5 .…”

“…It is usually associated with structural, functional, and molecular changes in spermatozoa. There are many endogenous and exogenous factors that cause asthenozoospermia, such as (1) abnormal semen liquefaction, (2) deleterious effect of seminal plasma, (2) endocrine abnormalities, (3) chromosomal abnormalities (diploidy, disomy, nulisomy, and microdelations of somatic and sex chromosomes in sperm cells), (4) epigenetic abnormalities (e.g., microRNA alterations), (5) specific mutations of genes (e.g., sperm mitochondria‐, annulus‐ and flagella‐related genes), (6) infections/inflammations in the urogenital system leading to leukocytospermia and consequently to oxidative stress (OS) in semen, (7) varicocele usually coexisting with OS, and (8) prolonged sexual abstinence, lifestyle and pollutants, which are also connected with OS 4,6–18 …”