Pregnancy rates after vasectomy: a survey of US urologists.

We surveyed 2000 US urologists using mailed questionnaires. The aim of this survey was to estimate the incidence of pregnancy after vasectomy and to gather information on the surgical methods used. Of 586 responding urologists, 538 reported performing vasectomies, and they reported a total of 177 pregnancies during the preceding 5 years. Ninety pregnancies (51%) were attributed to unprotected intercourse during the immediate post-vasectomy period. The remaining pregnancies were attributed to recanalization or other less common causes of method failure. Based on the number of vasectomies performed by these surgeons, about 1 pregnancy was reported per 1000 vasectomies. This is probably an underestimate of the true rate. The risk of pregnancy was lower following vasectomies by surgeons who performed more than 50 procedures per year.