Although vasectomies can be reversed, they should be regarded as permanent. Reversal is a trickier procedure, requiring more involved surgery, and success cannot be guaranteed. After reversal, sperm counts sometimes recur at only low levels, and antibodies may develop and attack existing sperm, making them unable to fertilize normally. Additional techniques to assist in restoring fertility are often available but may be costly, troublesome and ultimately unsuccessful. In general, success rates tend to be higher the sooner the vasectomy is reversed.
Some men choose vasectomy and opt for the security of banking sperm beforehand.
While this also cannot be guaranteed to lead to a successful pregnancy, many families feel better with this system in place. A discussion of vasectomy would not be complete without mentioning studies that show a possible increased risk of prostate cancer following the procedure, especially 20 or more years after the vasectomy. The jury is still out on whether this increased risk is even real. The difference is not large and the biological mechanism for the association is not understood. Some experts believe the results of the studies may best be explained if men who have vasectomies are simply more likely to see their doctor more often, giving them more opportunity to have the disease diagnosed.