Effects of sterilization on menstruation.

We surveyed 551 women more than a year after they or their husbands had had a sterilization operation. According to menstrual data from before and after the operation, a much greater proportion of women who had been sterilized had longer periods after the operation than before, but so did women whose husbands had had a vasectomy. Women who had taken an oral contraceptive before operation, had more days of bleeding and heavier bleeding than women who had been using other methods of contraception; those who had an intrauterine device removed had fewer days of bleeding after the sterilization operation. Discontinuing the previous contraception probably had a greater effect on menstruation than had the operation, for the effect was the same for those who had sterilization and the women whose husbands had an operation.