title: The risk of pregnancy after vasectomy.
abstract: OBJECTIVE
  To describe the pregnancy rates among women whose husbands underwent vasectomy.
  
  
  METHODS
  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.
  
  
  RESULTS
  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 7.4 (0.2, 14.6) 1 year after vasectomy and 11.3 (2.3, 20.3) at years 2, 3, and 5 [corrected].
  
  
  CONCLUSIONS
  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.
authors.affiliation: Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA. djj0@cdc.gov
authors.forename: Denise J
authors.initials: DJ
authors.lastname: Jamieson
authors.forename: Caroline
authors.initials: C
authors.lastname: Costello
authors.forename: James
authors.initials: J
authors.lastname: Trussell
authors.forename: Susan D
authors.initials: SD
authors.lastname: Hillis
authors.forename: Polly A
authors.initials: PA
authors.lastname: Marchbanks
authors.forename: Herbert B
authors.initials: HB
authors.lastname: Peterson
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D011247:Pregnancy / Q000706:statistics & numerical data*; D011446:Prospective Studies; D012307:Risk Factors; D014659:Vasectomy