The changing tide of human fertility

Abstract

Over the past half-century, the world has witnessed a steep decline in fertility rates in virtually every country on Earth. This universal decline in fertility is being driven by increasing prosperity largely through the mediation of social factors, the most powerful of which are the education of women and an accompanying shift in life’s purpose away from procreation. In addition, it is clear that environmental and lifestyle factors are also having a profound impact on our reproductive competence particularly in the male where increasing prosperity is associated with a significant rise in the incidence of testicular cancer and a secular decline in semen quality and testosterone levels. On a different timescale, we should also recognize that the increased prosperity associated with the demographic transition greatly reduces the selection pressure on high fertility genes by lowering the rates of infant and childhood mortality. The retention of poor fertility genes within the human population is also being exacerbated by the increased uptake of ART. It is arguable that all of these elements are colluding to drive our species into an infertility trap. If we are to avoid the latter, it will be important to recognize the factors contributing to this phenomenon and adopt the social, political, environmental and lifestyle changes needed to bring this situation under control.

Mechanism of Inflammatory Associated Impairment of Sperm Function, Spermatogenesis and Steroidogenesis

“…Evidence suggests that immunological and infectious etiologies contribute substantially to male infertility [accounting for 13–15% of cases (2)], a medical and social problem which in total is increasing worldwide ( 8 ). The contribution of inflammatory infertility may be underestimated as immune cell infiltration is observed in 20% of testicular biopsies of azoospermic infertile patients ( 9 ).…”

Targeted Analysis of HSP70 Isoforms in Human Spermatozoa in the Context of Capacitation and Motility

“…Many scientific studies demonstrate that male fertility is in decline, with an alarming decrease in sperm parameters observed over the past 50 years [ 59 , 60 , 61 , 62 ]. To understand the molecular mechanisms involved in male infertility, global mass spectrometry-based proteomic approaches have been used by different research groups to identify key proteins linked to infertility (e.g., see [ 63 , 64 , 65 , 66 , 67 , 68 , 69 ] for reviews).…”

Targeted analysis of HSP70 isoforms in human spermatozoa in the context of capacitation and motility

“…Many scientific studies demonstrate that male fertility is in decline, with an alarming decrease in sperm parameters observed over the past 50 years [59][60][61][62]. To understand the molecular mechanisms involved in male infertility, global mass spectrometry-based proteomic approaches have been used by different research groups to identify key proteins linked to infertility (e.g., see [63][64][65][66][67][68][69] for reviews).…”