Why increasing prevalence of male factor subfertikity

The another etiology of male factor subfertility:: Whats wrong with male population?? Disruption of embryonic programming and gonadal development during fetal life disruption of embryonal programming and gonadal development during fetal life. : Another such programme is Testicular  dysgenesis syndrome: an increasingly common developmental disorder with environmental aspects:

Recent reports have focused on various aspects of adverse trends in male reproductive health, A) such as the rising incidence of testicular cancer; B) low and probably declining semen quality; C) high and possibly increasing frequencies of undescended testis and hypospadias; and an apparently D) growing demand for assisted reproduction. There is reason to believe that poor semen quality, testis cancer, undescended testis and hypospadias are ever increasing symptoms in the last four decades .One  such example is rising prevalence of  testicular dysgenesis syndrome (TDS), which has now become  increasingly common due to adverse environmental influences. Experimental and epidemiological studies suggest that TDS is a result of disruption of embryonal programming and gonadal development during fetal life. What hormonal changes may occur with TDS ?? A study of reproductive hormone levels in 3‐months‐old infants found that cryptorchid boys had significantly elevated FSH and LH serum levels associated with reduced inhibin B concentrations compared with controls. Boys with hypospadias had similar changes in hormone levels. A large study on reproductive hormones in adult men found a shift towards lower serum testosterone levels, testosterone/LH ratio and higher serum LH levels in infertile men compared with proven fertile men from the same geographical area. These hormonal changes may be seen as a compensated Leydig cell failure, although these findings may also be explained as a response from Leydig cells to poor spermatogenesis.

Endocrine disrupter hypothesis

Testicular dysgenesis syndrome is undoubtedly a multifactorial disease. Established causes of severe forms of testicular dysgenesis syndrome (TDS), (TDS ) are 1)  primarily genetic e.g. 45,X/46/XY karyotype, 2)  androgen insensitivity and 3) SRY mutation, often resulting in the most severe cases with all TDS symptoms, including hypospadias, cryptorchidism and germ cell tumour. However, the recent quite significant increase in testicular cancer (400% in two generations  cannot be explained by genetic factors alone.