Male factor infertility

Male factor infertility
The male partner is directly responsible for 25% of cases of infertility and is thought to play a contributory role in another 25%. Male factor infertility implies a lack of sufficient numbers of competent sperm, resulting in failure to fertilize the normal ovum.
Spermatogenesis requires testicular growth & differentiation & it is under endocrine control by FSH & paracrine control by androgens produced by LH-stimulated Leydig cells. Spermatogenesis comprises the mitotic division of spermatogonia & meiotic division of spermatocytes. These will develop into spermatids which then transform into mature spermatozoa in a process called spermiogenesis. Genes involved in spermatogenesis are expressed on the Y chromosome. In human this process takes 74 days.

Causes of male infertility:
• Disorders of spermatogenesis:
Impaired spermatogenesis could result from defect in any of the above mechanisms. The normal scrotal temperature is 1 degree lower than the rest of the body temperature and a rise in scrotal temperature is found in undescended testes and varicocele wherein increased scrotal temperature may impair spermatogenesis. Micro deletions of Y chromosomes may lead to defective spermatogenesis. Impaired sperm production and sexual function may result from the intake of certain drugs such as some psychotropic drugs, anti-epileptic and antihypertensive agents, antibiotics and chemotherapeutic agents which adversely affect sperm production and sexual function.