Many women and/or men seek "permanent" sterilization as a technique of birth control when they consider they desire not to have children in the prospect. This can take the form of a fallopian tube ligation (tubal) in the female or a vas deferens ligation in the male. Some of these men and women subsequently change their minds and wish to have the "lasting" sterilization reversed. Luckily, the surgical blockage can be removed in most cases of ligation in either the male or female. If no other factor has occurred that would put off conception, then this "reversal" will usually result in conception. In women this is usually the case and pregnancy can be achieved in up to 90% of reversals depending on the type of ligation that was originally performed. In men, unfortunately, this is not always the case.