A vasectomy is generally considered one of the most permanent forms of birth control. It can, with some effort, be reversed, but with mixed success.
A vasectomy, as anyone considering vasovasostomy likely knows, consists of the surgical disconnection of the dual vas deferens, the tubes which lead from each testicle to the prostate. These tubes are then tied off or clipped and allowed to heal. In order to reverse this, the surgeon must remove the tied ends from the tubes and then rejoin them physically.
Success rates vary, largely dependent upon how long ago the original procedure was performed. Within three years of a vasectomy, the prospects for fertile reversal tend to be a bit better than fifty percent. Ten years or more indicates a chance somewhat under thirty percent.
One great "if" in the procedure is that your body may develop an immune response to its own sperm cells, creating antibodies to mark them for attack. This can occur as a result of the initial procedure or as a result of the reversal. While this is not dangerous to you, it may mean that you are wholly infertile; if sperm antibodies are contained in your semen when you attempt to copulate, your sperm likely will die off before they reach an ovum. Tests for sperm antibodies can be conducted before the procedure, to ensure that it will not be in vain, and also after, to check your progress. The odds of fertilization with sperm antibodies present are slim to none without the use of in vitro fertilization, a process that does not require the re-connection of your vas deferens. Consult with a fertility specialist before undergoing any surgical procedure so that you can be sure where lay the best odds of successful fertilization.
