Most men are very anxious about a vasectomy, as they are not sure what happens and are concerned that it may affect their libido or masculinity. This is not so. Sperm are produced by the testes throughout adult life at a relatively constant rate. The sperm enter a complex network of small tubules which unite to form the sperm tube (vas deferens). The sperm pass along this tube to a storage sac (the seminal vescicle) in the groin where they await the next ejaculation. The walls of the sperm storage sac secrete a fluid which nourishes the sperm, and along with an exudate from the prostate gland, forms 95% of the semen passed by the man during intercourse. When he ejaculates, the sperm and supporting fluid (called semen when combined) pass down the sperm tube to its junction with the urethra, and then along this tube to the outside of the penis. In the operation, a local anaesthetic numbs the side of the scrotum, and through a small incision, the doctor cuts, burns and ties the sperm tube (vas deferens) so no further sperm can pass along it from the testes. This may be done in the doctor's rooms, or as a day patient in a private hospital.
The procedure is very simple and brief, and no pain is felt.The man is not immediately sterile after the operation. Because sperm are stored in the sac above where the tube is tied, this must be emptied by about a dozen ejaculations over the next few weeks. It is normal to have a test done about six weeks after the operation to check that no sperm are getting through or remaining in storage. The couple can stop their other contraceptive measures after this test is confirmed. The male hormones which establish and maintain masculinity are also produced in the testicles. These are no affected in any way by the operation as they enter the blood stream directly from the testes and continue to function normally. The man's ejaculation is not affected either, as the fluid from the sperm storage sac is passed as normal.
2. Preventing the release of the egg (ovum) from the ovary.