Success
The use of microsurgery has increased the patency rate (the appearance of motile sperm in the ejaculate) to 97% within 3 years of a successful vasectomy (see table below).
| Time since vasectomy (yrs) | Patency Rate | Pregnancy Rate |
| < 3 | 97% | 75% |
| 3 – 8 | 88% | 50 – 55% |
| 9 – 14 | 79% | 40 – 45% |
| 15 – 19 | 70% | 30% |
| > 19 | 40% | < 10% |