If the sperms are present during surgery, success rates at our center exceeds of 95%.
In a large study of 1500 patients from multiple institutions, the success rate correlated with the length of time since vasectomy. The shorter the interval from vasectomy to reversal, the higher the success rate.
In men whose obstructed interval was less than 3 years, the likelihood of sperm present in the semen after reversal is as high as 95% and pregnancy was observed in 75% of the wives.
On the contrary, when the obstructed interval was greater than 15 years, only 70% of men will have sperm in their semen following reversal and the pregnancy rate was significantly lower at 30%.
In most men, i.e. those with obstructed intervals between 4-14 years, the likelihood of having sperm in the semen is about 80% with a pregnancy rate of 45-60%.
In interpreting this data, one should keep in mind that the age of the wives plays an important role in the overall pregnancy rate. Men who are older, i.e. those who have had long obstructed intervals, may have older partners. This difference may account for some of the pregnancy rate difference as outlined above.