Infertility and problems of impaired fecundity have been a concern through ages and is also a significant clinical problem today, which affects 8-12% of couples worldwide. Of all infertility cases, approximately 40-50% is due to "male factor" infertility and as many as 2% of all men will exhibit suboptimal sperm parameters. It may be one or a combination of low sperm concentration, poor sperm motility, or abnormal morphology. The rates of infertility in less industrialized nations are markedly higher and infectious diseases are responsible for a greater proportion of infertility. The present literature will help in knowing the trends of male factor infertility in developing nations like India and to find out in future, various factors that may be responsible for male infertility.

Trends of male factor infertility, an important cause of infertility: A review of literature.

It is predicted that Japan and European Union will soon experience appreciable decreases in their populations due to persistently low total fertility rates (TFR) below replacement level (2.1 child ...

https://www.physiology.org/doi/pdf/10.1152/physrev.00017.2015

Male Reproductive Disorders and Fertility Trends: Influences of Environment and Genetic Susceptibility

study question: Are temporal trends and values of semen quality parameters in France identifiable in partners of totally infertile women? summary answer: Among a sample of 26 609 partners of totally infertile women undergoing an assisted reproductive technology (ART) procedures in the whole of France over a 17-year period, there was a continuous decrease in semen concentration of about 1.9% per year and a significant decrease in the percentage with morphologically normal forms but no global trend for motility. what is known already: A global decrease in human sperm quality is still debated as geographical differences have been shown, and many criticisms have risen concerning studies with small and biased study populations or inappropriate statistical methodology. However, growing biological, toxicological, experimental and human exposure data support the endocrine disruptors’ hypothesis assuming that fetal exposure to endocrine disruptors could impair reproductive outcomes. study design, size, duration: This was a retrospective and descriptive study using data registered by Fivnat, the professional association in charge of statistics for ART in France during the 1989– 2005 study period. Data were provided by 126 main ART centres over the whole metropolitan territory. The source population included 154 712 men, aged 18– 70, who were partners of couples undergoing their first ART cycle and for whom semen quality indicators (concentration, total motility and percentage of morphologically normal forms), measured on fresh ejaculated semen, were available. participants/materials, setting, methods: The study population was 26 609 partners of women who had both tubes either absent or blocked. The temporal trends for each indicator of semen quality were modelled using a generalized additive model that allowed for nonlinear relationships between variables and were adjusted for season and age. In-depth sensitivity analyses included the reiteration of the analysis on data from a second spermiogram available for each man and on another subsample of men diagnosed as fertile. Variables such as centre, technique (standard in vitro fertilization or intra-cytoplasmic sperm injection) and an interaction factor between technique and time were also included in the model. main results and the role of chance: There was a significant and continuous decrease in sperm concentration of 32.2% [26.3– 36.3] during the study period. Projections indicate that concentration for a 35-year-old man went from an average of 73.6 million/ml [69.0– 78.4] in 1989 to 49.9 million/ml [43.5– 54.7] in 2005. A significant, but not quantifiable, decrease in the percentage of sperm with morphologically normal forms along the 17-year period was also observed. There was no global trend but a slight, significant increase in total motility between 1994 and 1998 was observed. The results were robust after sensitivity analysis. limitations, reasons for caution: Socioeconomic status could not be controlled for. Despite universal access to medical services in France, couples undergoing ART are expected to have a higher educational level on average compared with those of the general population. Therefore, the real values in the general population could be slightly lower than those presented and the decrease possibly stronger, as the population study is less likely to smoke or be overweight, two factors known to impair semen quality.

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Decline in semen concentration and morphology in a sample of 26 609 men close to general population between 1989 and 2005 in France

Occupational exposure to pesticides and consequences on male semen and fertility: A review

Reports regarding the changes in sperm concentration in different counties of the world are inconsistent. Furthermore, the reports that sprung up from specific epidemiological and experimental examinations did not include data of prior studies or geographical variations. The current study, following a previous report of massive fall in semen volume over the past 33 years, attempts to delineate the trend of altering sperm concentrations and factors responsible for this by reviewing article published from 1980 to July 2015 with geographic differences. The current study identified an overall 57% diminution in mean sperm concentration over the past 35 years ( r = -.313, p = .0002), which, when analyzed for each geographical region, identified a significant decline in North America, Europe, Asia, and Africa. An increasing trend of sperm concentration was identified only in Australia. The association of male age with such a trend ( R2 = .979) is reported. The authors also correlated male fertility with sperm concentration. Thus, this comprehensive, evidence-based literature review aims to concisely and systematically present the available data on sperm concentration from 1980 to 2015, as well as to statistically analyze the same and correlate male health with the declining pattern of sperm count in a single scientific review to serve the scientific research zone related to reproductive health. It points to the threat of male infertility in times ahead.

https://journals.sagepub.com/doi/pdf/10.1177/1557988316643383

The Disappearing Sperms: Analysis of Reports Published Between 1980 and 2015.

Concerns about the worldwide decline in semen quality over the past 50 years are increasing. Western countries have shown a decline in semen quality. However, in non-Western countries studies are sparse. We investigated trends in semen parameters between 1996 and 2007 in the Sfax area of southern Tunisia in a sample of 2940 men in infertile relationships. Age at semen collection, duration of sexual abstinence, volume of seminal fluid, the sperm count, percentages of motile and morphologically normal spermatozoa, and semen leukocyte concentration were determined. Linear regression was used to examine trends over time in sperm count, sperm motility, normal morphology, and semen leukocyte concentration. Mean age and semen volume did not change between 1996 and 2007. Data adjusted for age and abstinence showed a decreasing trend in sperm count and percentage of normal morphology over the last 12 years (R2 = 0.71, P = .0004, and R2 = 0.87, P < .0001, respectively). There was no significant change in sperm motility. However, semen leukocyte concentration increased significantly over time (R2 = 0.38, P = .03). These results coincide with the high prevalence of genital infectious diseases in the Sfax area, suggesting that infection may be a potential contributing factor in semen quality decline.

N. Chakroun Feki

Papers

Semen quality decline among men in infertile relationships: experience over 12 years in the South of Tunisia.

Mobility of trace metals and microbiological pollution from dredged sediments to the Gulf of Gabes, Tunisia

Mechanical characterization of treated harbour sediments for road applications