Male Infertility

Testicular failure

The semen may contain no sperms (azoospermia), few sperms (oligospermia) or predominantly abnormal sperms. The cause is pre­sumably some form of testicular dysfunction which may follow mumps infection, exposure to radiation or testicular trauma but is more often unknown. The normal feedback mechanism to control the production of gonadotrophic hormones is disturbed if there is testicular atrophy and the serum levels of luteinising hormone and follicle-stimulating hormone will be high. In some cases of azoospermia the testicular biopsy shows a failure of sperm development. Many treatments have been attempted but the results have been disappointing.

Obstruction

Azoospermia may also be due to obstruction to the pathway of spermatozoa from the testis via the epididymis to the ejaculatory ducts. The testicular biopsies will show active spermatogenisis. If the site of the obstruction can be identified by vasography it may be possible to perform a bypass operation. Unfortunately, even in the best hands, the results of epididymovasostomy are poor.

In some couples there appears to be an immunological cause for the infertility with clumping of sperms exposed to serum or cervical mucous.

Intracytoplasmic sperm injection

Intracytoplasmic sperm injection has revolutionised the management of male factor infertility. Spermatozoa harvested from the ejaculate, by aspiration of the epididymis or even from testicular biopsy, can be injected in vitro into ova obtained from the mother. Embryos are then transferred into the mother’s uterus at the 4—6 cell stage.

Vasectomy for sterilisation

Vasectomy for sterilisation is one of the most commonly per­formed operations throughout the world. It should only be undertaken after the couple has been carefully counselled. They need to know that the operation is performed to make the man permanently sterile. They should be warned that they should continue with their normal contraceptive precautions until the success of the operation has been confirmed by semen analysis performed 12—16 weeks after surgery. They should also be warned of the remote but important possibility of spontaneous recanalisation which may restore fertility unexpectedly.

Vasectomy is easily and painlessly performed under local anaesthetic. The vasa are delivered through tiny bilateral or a single midline scrotal incision. For medicolegal reasons it is wise to remove a segment of each vas to prove that it has been successfully divided. Burying the cut ends or turning them back on themselves probably helps to prevent them rejoining.

Reversal of vasectomy may not restore fertility even if technically successful because of the presence of autoantibodies developed against the sequestered sperms. A success rate of 60—8 0 per cent may be possible if the operation is performed within 3—4 years of vasectomy.