madman
Super Moderator
ABSTRACT
Male infertility accounts for about 30% of the causes of couple infertility and has become a public health concern. Male infertility may be caused by several factors occurring in isolation or association with several complex syndromes. Despite the importance of semen analysis in the initial investigation of infertility, it has been estimated that 15% of infertile men present normal sperm, a proportion that calls for additional tests to further investigate cases of infertility and accurately determine the factors that alter ejaculate quality. In addition to semen analysis parameters, genetics has been drawing attention. The incorporation of genetic diagnostic methods in the routine practice of andrology laboratory is an important step to further improve assisted reproductive technologies. The present study described the current status of the main methods used in male infertility investigation.
INTRODUCTION
Fertility is defined as the ability of a couple to establish a clinical pregnancy (Zegers-Hochschild et al., 2017). On the other hand, infertility has been recently considered an important public health problem, characterized by the World Health Organization (WHO) as the failure to attain and maintain pregnancy after twelve months of attempts, without the use of contraceptive methods (Agarwal et al., 2015; revised by Vander Borght & Wyns, 2018).
One in seven couples in developed countries and one in four couples in developing nations suffer from reproductive infertility. Depending on the region, fertility rates may reach 30% and affect more than 180 million people, mostly in developing countries (Santoro et al., 2016; Mascarenhas et al., 2012). Men are responsible for 20-30% of infertility cases but contribute to 50% of the general cases, with male infertility affecting about 10% of couples of reproductive age worldwide and, in many cases, the possibility of treatment (Agarwal et al., 2015).
Infertile males have abnormal spermograms, and etiologies may include environmental, dietary, medical, genetic, and physiological factors (Auger et al., 2001; Kenkel et al., 2001). Male infertility is the result of several factors that may occur in isolation or association with several complex syndromes. The causes may be related to anatomical malformations, gametogenesis dysfunctions, immunological disorders, ejaculatory disorders, or acquired through exposure to certain environmental agents (Kuhtz et al., 2014).
*This paper aims to analyze the main current aspects of male infertility research, as well as to describe the main genetic alterations related to infertility and the effects of male age on semen quality.
*AGE AND FERTILITY
*OXIDATIVE STRESS AND SPERM VIABILITY
*FERTILITY AND GENETIC ABNORMALITIES
*KLINEFELTER SYNDROME
*Y CHROMOSOME DELETIONS
*SPERM QUALITY AND DNA INTEGRITY
*SPERM QUALITY DIAGNOSTIC METHODS
-SPERMOGRAM
-SPERM DNA TESTING
-PROTEOMIC ANALYSIS
-OXIDATIVE STRESS ANALYSIS
CONCLUSION
Further studies are needed to define which factors alter the quality of the ejaculate and the specific parameters affected. Delaying fatherhood is an emerging trend, and this new profile has served as a warning for the possible causes of negative effects of aging on fertility.
With the evolution of assisted reproductive technologies, it is possible to observe even wider multifactorial causes of infertility and different, more specific shades to male factor infertility. In addition to semen parameters, genetics and the anomalies secondary to germ cell mutations have commanded attention. Individuals with somatic chromosomal anomalies, with an atypical number of chromosomes or structural abnormalities, have a higher probability of infertility, repeat miscarriages, and of or having offspring with severe disabilities.
The incorporation of genetic diagnostic methods in the routine practice of andrology laboratories is an important step to further improve assisted reproductive technologies, minimize the adverse effects of gamete manipulation, and optimize results. During the fertility evaluation process of a couple, careful analysis is warranted to identify potential genetic anomalies and ensure accurate genetic counseling.
Different studies have elaborated on the risks associated with decreases in semen quality and fertility introduced by aging. However, due to the diversity of reported results, additional studies examining the relationship between age and semen quality/fertility are needed before definitive conclusions can be drawn. These studies should include large populations and apply methodological rigor to improve the reliability of results.
In recent years, proteomic analyses have been used to characterize the protein profiles of the ejaculate of men with different clinical conditions. Recent advances in proteomic techniques, especially in two-dimensional polyacrylamide gel electrophoresis and mass spectrometry, have enhanced the study of spermatozoa and sperm proteins. One of the advantages of gel electrophoresis is that the technique allows the identification of various specific sperm proteins. Proteomics has also provided additional insight into the role of the proteins involved in sperm processes and the differentiation between normal and abnormal states. In addition, studies on sperm proteome demonstrated the importance of post-translational modifications and their ability to cause physiological changes in sperm function. The recent advances in diagnostic techniques may provide information on sperm function and dysfunction and be implemented in human reproduction clinics to identify and characterize the damages that cause male infertility.
Male infertility accounts for about 30% of the causes of couple infertility and has become a public health concern. Male infertility may be caused by several factors occurring in isolation or association with several complex syndromes. Despite the importance of semen analysis in the initial investigation of infertility, it has been estimated that 15% of infertile men present normal sperm, a proportion that calls for additional tests to further investigate cases of infertility and accurately determine the factors that alter ejaculate quality. In addition to semen analysis parameters, genetics has been drawing attention. The incorporation of genetic diagnostic methods in the routine practice of andrology laboratory is an important step to further improve assisted reproductive technologies. The present study described the current status of the main methods used in male infertility investigation.
INTRODUCTION
Fertility is defined as the ability of a couple to establish a clinical pregnancy (Zegers-Hochschild et al., 2017). On the other hand, infertility has been recently considered an important public health problem, characterized by the World Health Organization (WHO) as the failure to attain and maintain pregnancy after twelve months of attempts, without the use of contraceptive methods (Agarwal et al., 2015; revised by Vander Borght & Wyns, 2018).
One in seven couples in developed countries and one in four couples in developing nations suffer from reproductive infertility. Depending on the region, fertility rates may reach 30% and affect more than 180 million people, mostly in developing countries (Santoro et al., 2016; Mascarenhas et al., 2012). Men are responsible for 20-30% of infertility cases but contribute to 50% of the general cases, with male infertility affecting about 10% of couples of reproductive age worldwide and, in many cases, the possibility of treatment (Agarwal et al., 2015).
Infertile males have abnormal spermograms, and etiologies may include environmental, dietary, medical, genetic, and physiological factors (Auger et al., 2001; Kenkel et al., 2001). Male infertility is the result of several factors that may occur in isolation or association with several complex syndromes. The causes may be related to anatomical malformations, gametogenesis dysfunctions, immunological disorders, ejaculatory disorders, or acquired through exposure to certain environmental agents (Kuhtz et al., 2014).
*This paper aims to analyze the main current aspects of male infertility research, as well as to describe the main genetic alterations related to infertility and the effects of male age on semen quality.
*AGE AND FERTILITY
*OXIDATIVE STRESS AND SPERM VIABILITY
*FERTILITY AND GENETIC ABNORMALITIES
*KLINEFELTER SYNDROME
*Y CHROMOSOME DELETIONS
*SPERM QUALITY AND DNA INTEGRITY
*SPERM QUALITY DIAGNOSTIC METHODS
-SPERMOGRAM
-SPERM DNA TESTING
-PROTEOMIC ANALYSIS
-OXIDATIVE STRESS ANALYSIS
CONCLUSION
Further studies are needed to define which factors alter the quality of the ejaculate and the specific parameters affected. Delaying fatherhood is an emerging trend, and this new profile has served as a warning for the possible causes of negative effects of aging on fertility.
With the evolution of assisted reproductive technologies, it is possible to observe even wider multifactorial causes of infertility and different, more specific shades to male factor infertility. In addition to semen parameters, genetics and the anomalies secondary to germ cell mutations have commanded attention. Individuals with somatic chromosomal anomalies, with an atypical number of chromosomes or structural abnormalities, have a higher probability of infertility, repeat miscarriages, and of or having offspring with severe disabilities.
The incorporation of genetic diagnostic methods in the routine practice of andrology laboratories is an important step to further improve assisted reproductive technologies, minimize the adverse effects of gamete manipulation, and optimize results. During the fertility evaluation process of a couple, careful analysis is warranted to identify potential genetic anomalies and ensure accurate genetic counseling.
Different studies have elaborated on the risks associated with decreases in semen quality and fertility introduced by aging. However, due to the diversity of reported results, additional studies examining the relationship between age and semen quality/fertility are needed before definitive conclusions can be drawn. These studies should include large populations and apply methodological rigor to improve the reliability of results.
In recent years, proteomic analyses have been used to characterize the protein profiles of the ejaculate of men with different clinical conditions. Recent advances in proteomic techniques, especially in two-dimensional polyacrylamide gel electrophoresis and mass spectrometry, have enhanced the study of spermatozoa and sperm proteins. One of the advantages of gel electrophoresis is that the technique allows the identification of various specific sperm proteins. Proteomics has also provided additional insight into the role of the proteins involved in sperm processes and the differentiation between normal and abnormal states. In addition, studies on sperm proteome demonstrated the importance of post-translational modifications and their ability to cause physiological changes in sperm function. The recent advances in diagnostic techniques may provide information on sperm function and dysfunction and be implemented in human reproduction clinics to identify and characterize the damages that cause male infertility.
