Relationship between time period after vasectomy and the reproductive capacity of sperm obtained by epididymal aspiration

BACKGROUND: It is not well defined whether the elapsed time after vasectomy has any influence on the outcome of IVF-ICSI using epididymal sperm. We analysed retrospectively the results of 151 ICSI cycles in which sperm of vasectomized men were used at different time periods after vasectomy. METHODS: Oocytes were obtained after a desensitizing ovarian stimulation protocol using GnRH agonist in association with recombinant FSH and HCG. Sperm were retrieved by percutaneous epididymal sperm aspiration. The cycles were split into three groups: < or =10 years after vasectomy (group 1, n = 47), 11-19 years after vasectomy (group 2, n = 79), and > or =20 years after vasectomy (group 3, n = 25). RESULTS: As might be expected, the mean age of men differed in the three groups (group 3 > group 2 > group 1), and the mean age of the women was also significantly higher in group 3 than in groups 1 and 2, although no differences were described between groups 2 and 3. All other laboratory and clinical parameters were similar in the three groups. Ongoing pregnancy and implantation rates (34, 25, 8% and 22, 15, 6% respectively) decreased significantly from group 1 to group 3. CONCLUSION: Pregnancy and implantation rates after ICSI with sperm from vasectomized men are negatively correlated with the time interval from vasectomy, which cannot be explained purely by male or female ageing.