Tubal sterilization: findings in a large prospective study.

Of the 17032 women taking part in a large prospective study of the beneficial and harmful effects of different contraceptive methods, 2243 (13%) had undergone tubal sterilization by the end of 1981 while another 3551 (21%) had husbands who had undergone vasectomy. The most commonly used female sterilization procedure was laparoscopic tubal diathermy. About 19% of all operations were carried out at the time of a delivery or during the subsequent 4 weeks. In total, 16 accidental pregnancies have occurred in the sterilized women, the failure rate during the 12 months after surgery being 0.37 per 100 woman-years and the rate during the subsequent months being 0.10 per 100 woman-years. Of the 16 accidental pregnancies, seven were ectopic. In an analysis comparing women who had undergone tubal sterilization with those whose husbands had undergone vasectomy, there was little evidence of any excess occurrence of gynaecological or psychiatric disorders in the former group.