To describe the pregnancy rates among women whose husbands underwent vasectomy.
Between 1985 and 1987, 573 women aged 18–44 years whose husbands underwent vasectomy in medical centers in 5 U.S. cities were enrolled in the U.S. Collaborative Review of Sterilization, a prospective cohort study of male and female sterilization. Women were interviewed by telephone at 1, 2, 3, and 5 years after their husbands underwent vasectomy.
Among the 540 eligible women at risk for pregnancy, there were 6 pregnancies occurring from 6 to 72 weeks after vasectomy. The cumulative probability of failure per 1,000 procedures (95% confidence interval) was 9.4 (1.2, 17.5) 1 year after vasectomy and 11.3 (2.3, 20.3) at years 2, 3, and 5.
Couples considering vasectomy should be counseled about the small, but real, risk of pregnancy following the procedure and that men are not sterile immediately after vasectomy.
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