Post-op Semen Analysis - Zero or Declining

Number of Months After Surgery Where 0 Result Observed Likelihood of Having Future Test with Sperm Present
VV/VV Surgery VV/EV Surgery EV/EV Surgery
0-2 Months 48% 50% 45%
2.1-4 Months 37% 33% 33%
4.1-7 Months 15% 14% 29%
7.1-10 Months 17% 20% 14%
10.1-18 Months 10% 0% 14%

*Results last updated 11/10/2022.  Data represent all-comer, first-time reversals.

Frequently Asked Questions

Men with multiple 0's in a row are less likely to experience a return of sperm compared to those who experience fewer 0 sperm counts. 

Technically, sperm can return as far out as 2 years or more post vasectomy reversal, and as noted in the table above, even if men have no sperm out to 1 year, there is still a percentage that will go on to have sperm return.  However, we typically make a judgment call around 12 months post-reversal.  At that point, if the couple has not achieved a pregnancy and the sperm count is 0, this is a reasonable time to consider alternative options.

There are several potential options:

  • Redo vasectomy reversal.  If this is a first-time redo, the chance of getting sperm back is approximately 60%.  Of those who do get sperm back, 20-30% of those will go on to scar down later (delayed stenosis). 
  • In-vitro fertilization (IVF/ICSI)
  • Wait additional time.  Note the chances for return of sperm in the table above.
  • Donor sperm with intrauterine insemination (IUI)
  • Adoption

Maybe.  There are limited data that men with 0 sperm may experience a return of sperm (~10%) if they take prednisone.  However, it is not clear if their chances are higher compared to if they don't take prednisone. 

In cases where sperm were initially present, and then the count goes to 0, there are three common causes:

  1. The tube has temporarily narrowed.  In some cases, this is a normal part of healing.  Just as a scar becomes bigger and thicker for the first few months, so too, the area which was sewed back together becomes more narrowed.  In some cases, this will open up on its own, while in other cases, it will remain blocked.  We do not have good predictors as to who will experience which outcome. 
  2. The surgical repair has separated (i.e. ripped apart).  In most cases, patients will not feel when this occurs.  This can only be confirmed at the time of a redo surgery.
  3. The surgical repair has stenosed (closed down).  Sometimes, scar tissue will close the repair and will prevent sperm from getting across the area of repair. 

Unfortunately, the only way to know for sure is to examine the area of repair surgically.  There are not any imaging studies or laboratory tests which can tell you why it has changed or is at 0. 

This is a good question, and there isn't a perfect answer.  Keep in mind that sperm counts will commonly, naturally fluctuate by large amounts between tests.  One specific study which evaluated changes in sperm counts within the same individual over time showed a 400-500% variability from one test to the next.  However, if there is a clear trend over multiple tests (i.e. first test showed 80 million, 2nd one 20 million, 3rd one 5 million), this would suggest that the area is scarring down. 

In general, if your current test is lower than your last, there are a few things you can consider:

  • Repeat the test
  • Obtain a full semen analysis (one that includes motility).  If the count is lower but the motility is good, this is a good sign.  Decreased motility can be an early sign of progressive scarring. 
  • Starting prednisone.  There are very limited data which suggest that prednisone may increase counts.  However, it is currently not clear if the counts remain improved after stopping prednisone (most likely not, based on one study), or if taking prednisone actually improves long-term outcomes or pregnancy rates (also likely not, based on existing data).  We currently have an ongoing study to try to determine if prednisone truly does improve outcomes or not. 
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