A couple comes for evaluation of infeility. The HSG was normal but semen analysis revealed azoospermia. What is the diagnostic test to differentiate between testicular failure and vas deferens obstruction?
Serum FSH
Karyotyping
Testosterone levels
Testicular FNAC
Ans: A. Serum FSH(Ref. Ganong 25Ie p419, 425, 24Ie p427)Prior to initiating treatment for a couple, in whom the man has azoospermia, it is impoant to distinguish whether the lack of sperm in the ejaculate is from an obstructive or non-obstructive process.The presence of normal volume testes with bilaterally indurated epididymis and/or absent vas deferens will point to an obstructive etiology for azoospermia.A history of cryptorchidism in the presence of small or soft testes suggests non-obstructive azoospermia, especially if associated with an elevated serum (FSH) level.A decreased spermatogenesis leads to decrease in production of inhibin, which causes an elevation in FSH.