Whether the husband gets a vasectomy or the wife gets a tubal ligation is usually decided by who has the strongest will. Vasectomies and tubal ligations are safe surgeries, but the operation on a man is a simple cutting under the skin in an office, while the operation on a woman requires going into her belly in an operating room. Over the long haul, they both are safe and effective in preventing pregnancies.

Two studies seemed to show that having a vasectomy increases a man's chances of getting prostate cancer, but more recent studies show no increased risk. When scientists compare two variables to see if one causes the other, they should determine whether one factor causes the other, or is just associated with it. They use two study groups: men who have had vasectomies and those who have not. Men who have had vasectomies tend to be more sexually active than those who have not had this procedure; otherwise, they wouldn't need to have the vasectomy done. Three recent studies show that increased sexual activity is a risk factor for prostate cancer. Those at increased risk include men who have the earliest first sexual intercourse, the most partners, the most marriages and the most frequent orgasms. However, at present most doctors feel that sexual activity is not a risk factor for prostate cancer. Men who have had vasectomies are also less likely to use condoms because they don't have to worry about pregnancy, so they are more likely to pick up venereal diseases that may or may not be associated with prostate cancer.

Doctors cut the spermatic cord as it leaves the testicles to carry sperm to the outside. Beyond the cut, two glands, the prostate and seminal vesicles, attach to and supply most of the ejaculatory fluid. A vasectomy does not change a man's hormone levels or the appearance or amount of fluid in his ejaculate. One study shows that you must be cautious after you have had a vasectomy. Sometimes sperm hides in the tubes for months. The usual waiting period is to check a man six weeks after he has had a vasectomy to see if any sperm are still in his ejaculate. This study shows that you have to wait six months to be checked to see if it is safe to make love without causing a pregnancy.