Long-term risk of menstrual disturbances after tubal sterilization.

We analyzed data from the Walnut Creek Contraceptive Drug Study to compare the menstrual characteristics of 719 women who had tubal sterilizations and 1083 women whose partners had undergone a vasectomy. Study participants were enrolled from 1968 to 1972 and followed up through 1976. The tubal sterilization group had slightly increased, though in most instances not statistically significant, risks of moderate to severe menstrual cramps and adverse menstrual bleeding. At follow-up intervals longer than 2 years, the tubal sterilization group had significantly increased risks of abnormal menstrual cycles and combinations of two or more adverse menstrual outcomes. Tubal sterilization was not associated with an increased risk of premenstrual symptoms. These findings suggest that the types of tubal sterilization procedures which were performed during the early 1970s possibly carry some increased risk of menstrual disturbances, particularly abnormal cycles, and that it may take more than 2 years for the increased risk to become apparent.