Vasectomy Failure: Why Do Vasectomies Fail?
November 17, 2024
Vasectomy failure is possible. No birth control method is 100% effective.
Although no method is 100% effective, vasectomy can be close to 100% effective at preventing pregnancy.
This high rate of effectiveness can only be achieved if the most up-to-date techniques are used during the vasectomy procedure.
Older vasectomy methods that involve tying, cutting, and removing a small section of each vas deferens (ligation and resection) have been demonstrated to have failure rates as high as 10%.
These older vasectomy methods are responsible for many of the stories we have all heard about vasectomies failing.
If you are aware of someone having a vasectomy failure then most likely they had one of the older vasectomy techniques. Unfortunately, many vasectomy providers continue to use older techniques that can result in unacceptably higher rates of vasectomy failure.
You may ask yourself why do these providers continue to use methods if they are not as effective as other modern methods of vasectomy?
The two simplest answers to explain this question are these providers are:
- More comfortable using the methods they were originally taught.
- Not performing enough vasectomies to notice small differences in failure rates.
Regarding point #2 above…if a vasectomy method has a failure rate of 0.5% (5 out of 1000) then you have to do a lot of vasectomy procedures to begin to notice these failure.
With a 0.5% failure rate, a vasectomy provider who performs 300 vasectomy procedures may observe a failure every 1 to 2 years. A provider who performs 1000 vasectomy procedures per year may observe up to 5 vasectomy failures each year.
The perception of the lower volume provider is that vasectomy failures are uncommon. The perception of the higher volume provider is that vasectomy failure is more common. The higher volume vasectomy provider will be more acutely aware of their failure rate.
His Choice No Cut Vasectomy is a modern, no scalpel, minimally invasive vasectomy technique.
Instead of tying and cutting, the His Choice method involves lightly coagulating (burning) the inside of the top cut portion of the vas deferens and fascial interposition of the lower cut end of the vas deferens (diverting the two cut ends away from each other so they don’t touch and have time to heal closed).
- The vasectomy failure rate with the techniques used in the His Choice vasectomy method is approximately 0.3% (3 out of 1000 patients) in the first three months.
- Once the after vasectomy semen sample confirms the absence of sperm then the chance of a later vasectomy failure drops to approximately 0.05% (5 out of 10,000 patients).
His Choice vasectomy is extremely reliable once the three month after vasectomy semen sample confirms a negative sample. Although 0.05% chance of failure with the His Choice method is low there will be some rare failures with any method.
No method is 100% perfect…but we can get you close!
Contraceptive failure: Why do vasectomies fail?
Why do vasectomies fail? Vasectomies fail for two reasons:
- Patient noncompliance
- Reconnection of the vas deferens
Patient noncompliance. Most vasectomy ‘failures’ resulting in pregnancies happen within the first 3 months of the vasectomy procedure because patients do not always follow after vasectomy instructions.
Patients are advised to continue using effective birth control until their after vasectomy semen sample confirms the procedure has been successful.
Many patients will become lax in their use of birth control immediately after their vasectomy. These patients either do not realizing or are dismissive of the fact there are live sperm stored above the vasectomy sites. This is the most common reason for getting pregnant soon after having a vasectomy.
Most of these early pregnancies are not usually the result of a vasectomy failing. Instead, most of these early pregnancies are the result of failure to follow instructions.
Vas deferens reconnections. Reconnection of the vas deferens can occur after vasectomy. The divided ends can rejoin through healing tissue and result in live sperm crossing the vasectomy site. Most reconnections happen within the first 3 months of the vasectomy but a small number of reconnections can happen 12 months or more after vasectomy.
Most common reason for vasectomy failure: Noncompliance
The most common reason for ‘vasectomy failure’ is patient noncompliance. Noncompliance is the medical term for not following medical advice.
There are millions of live sperm stored inside the pelvis and above the vasectomy sites in the scrotum. Even after a successful vasectomy, patients have live sperm stored above the vasectomy sites and inside enlarged portions of the vas deferens behind the prostate.
These sperm will remain there until they spill out into the urine, slowly die and get resorbed, or are released with ejaculation. There are millions of sperm stored inside the tubes above the vasectomy sites. Some are healthy and motile. Some are healthy but sluggish. Some are deformed and do not swim well or may not swim at all. Many sperm are dead and adherent to the walls of the vas deferens.
Most of the healthy, motile sperm will be evacuated by ejaculation within the first six (6) weeks of the vasectomy procedure. These are the sperm that can cause pregnancy soon after vasectomy.
Many pregnancies after vasectomy are caused within the first 3 months from live healthy sperm above the vasectomy sites. This is the most common reason for pregnancy after vasectomy.
We strongly recommend you use an effective form of birth control after your vasectomy procedure until semen sample testing confirms the absence of motile sperm.
Vasectomy failures are most likely to happen early after vasectomy. Early means within the first several months.
Early vasectomy failures are due to both patient noncompliance and reconnection of the vas deferens (occlusive failure).
The way you can diagnosis the cause of the early failure is with the results of the semen sample. Failures due to patient noncompliance are usually diagnosed when a patient reports pregnancy within the first 3 months of vasectomy but their 3 month after vasectomy semen sample is negative for motile sperm.
The chance of an early vasectomy failure resulting in pregnancy after a His Choice Vasectomy procedure is 0.3% or 3 out of every 1000 patients.
Second reason for vasectomy failure: Early occlusive failure
Remember the famous line in the movie Jurassic Park, “Life will find a way…”
The vas deferens tubes can reconnect in the right circumstances.
If a vasectomy is going to fail the majority of the time it will happen during active healing phase. This is within the first three months of a vasectomy procedure. This is why the semen sample is scheduled 3 months after a His Choice vasectomy.
The 3 month time frame gives patients time to clear all of their sperm (both dead and alive) and also detect an early reconnection. Approximately 95% of patients will have a negative semen sample 3 months after their vasectomy. The remaining 5% may need an additional 1 to 2 months to clear residual dead sperm.
Reconnections of the vas deferens are most likely to happen within the first 3 months.
Early occlusive vasectomy failure
Early occlusive failure is the most common time to have a vasectomy failure.
This occurs when the upper and lower ends of the vas deferens come back into alignment after the vasectomy. The body responds to tissue damage from the vasectomy with healing tissue. The medical term for early healing tissue is granulation tissue.
After vasectomy, the testicles continue to make sperm. These sperm will escape the lower end and can create small channels through the granulation tissue. If any of these channels connect to the upper vas deferens sperm flow can be restored. This reconnection can result in live sperm getting across the vasectomy site.
As time passes after the vasectomy, soft granulation tissue is replaced with more solid, longer lasting collagen fibers (scar tissue). This is why later vasectomy occlusive failures are less common. The sperm cannot usually penetrate through this more durable collagen fibers.
Sperm are like trapped miners after vasectomy
A helpful analogy is to consider sperm to be like miners trapped in a collapsed tunnel. As soon as the tunnel collapses, the miners will start digging to find their way out. Many will not make it…but a lucky few may be able to create small escape passages to the outside world.
Time is of the essence. The best chance for the miners to escape is within hours to days of the tunnel collapse. The longer they take to find an exit then their chance of survival will decrease because they will run out of food and air. As more time passes, the chances of escape rapidly decreases. The same is true after vasectomy.
This is why the most likely time for occlusive vasectomy failure (reconnection) is within the first 3 months of having a vasectomy.
Providers who perform traditional vasectomy and simply remove a section of the vas deferens are not understanding and accounting for the ability of sperm to be able to penetrate the early healing tissue and establish a reconnection. This is why the His Choice method uses coagulation of the upper end and diversion of the two cut ends. Both the burning and the diversion minimize the risk of failure.
Early occlusive failures are diagnosed when a patient reports pregnancy soon after vasectomy and the 3 month after vasectomy semen sample shows motile sperm.
The chance of early vasectomy failure after a His Choice Vasectomy is 0.3% or 3 out of every 1000 patients.
Most of the patients in the 0.3% failure group will not be ‘vasectomy procedure failure’ but will more likely to be from residual upstream sperm and patients prematurely stopping birth control. Some of the patients in the 0.3% failure group will be due to occlusive vasectomy failure… or a failed vasectomy.
Third reason for vasectomy failure: Late occlusive failure
Late occlusive failure is defined as the presence of any motile (living, moving) sperm twelve (12) months or more after a vasectomy procedure. The chance of a late vasectomy failure with the His Choice vasectomy method is 0.05%.
Late occlusive vasectomy failure can sometimes be difficult to detect.
Late occlusive failure can occur because of small, early reconnections that were not detected by semen analysis or because of the development of a late reconnection.
Small early reconnections. Most occlusive failures can be diagnosed with today’s modern testing methods. If the vas deferens tubes do reconnect you will usually get large numbers of motile sperm getting across the vasectomy sites. Sperm in large numbers are easy to identify. Occasionally, early reconnections will result in sperm in very small numbers crossing the vasectomy site and these sperm can be hard to detect because of the low numbers.
Late reconnections. Late reconnections are also possible but not as common as early reconnections.
Most reconnections happen within the first 3 months of the vasectomy procedure. The soft, granulation tissue that forms immediately after a vasectomy procedure is gradually replaced by more solid, collagen containing scar tissue. The sperm have a much harder time penetrating this collagen containing scar tissue. So if they are going to ‘break through’ it is usually in the first several months of the vasectomy procedure.
Once a three month after vasectomy semen sample confirms the absence of motile sperm, the chance of late occlusive vasectomy failure after His Choice Vasectomy decreases to 0.05% … or 5 out of every 10,000 patients.
Late vasectomy failures are usually diagnosed by a confirmed pregnancy 12 months or more after the vasectomy procedure.
Many of the patients who have late vasectomy failures will show motile sperm in their semen sample test.
Amazingly some of the patients who have late vasectomy failure will not have detectable sperm in their semen sample.
Semen sample testing is not as accurate as most people believe for detecting sperm in small amounts.
How many semen sample test should be done after vasectomy?
We recommend one after vasectomy semen sample test after vasectomy. The key is waiting for approximately 3 months and having at least 20 ejaculations before having the semen tested.
We recommend this one semen sample test be done three (3) months after vasectomy but only after having a minimum of twenty (20) ejaculations during within the first three (3) month of the vasectomy.
Both conditions have to happen: waiting 3 months and also having a minimum of 20 ejaculations.
- Minimum of 20 ejaculations: Gets most of the live, pregnancy causing sperm out.
- Waiting 3 months: It takes time for the dead sperm stuck to the walls of the tubes above the vasectomy site to release. We are also giving enough time to allow for detection of any early reconnection.
Most vasectomy occlusive failures will happen within the first 3 months of having a vasectomy. Most of these occlusive failures will result in live sperm getting across the vasectomy sites.
One single test is all that is required for most patients to prove a His Choice Vasectomy was effective.
If your 3 month after vasectomy semen sample is negative for motile sperm your chances of causing pregnancy in the future are extremely low.
Why a single semen sample test 3 months after vasectomy?
His Choice vasectomy is highly effective. Most occlusive failures happen within the first 3 months of the procedure.
The single 3 month semen sample is designed to allow patients enough time to clear residual sperm (both dead and alive) from their vas deferens but also enough time to detect any possible early reconnection.
You can think of the 3 months sample as the earliest time to both prove that the vasectomy worked and also detect most reconnections of the vas deferens.
You are getting the best detection of both situations by waiting 3 months after the vasectomy.
Do you need more than one semen sample test after vasectomy?
Some vasectomy providers recommend a minimum of two semen sample tests after vasectomy. A few may perform 3 or 4 semen samples after vasectomy.
Most providers who recommend performing multiple semen sample test after vasectomy use older vasectomy techniques that have been associated with higher vasectomy failure rates. Some of these older, conventional vasectomy techniques can result in vasectomy occlusive failure in up to 9% of patients.
Even if these providers are not using older techniques many of them have been adversely influenced by their recollections or experience with vasectomy failures resulting from older vasectomy techniques.
Providers who perform these techniques may experience more failures and may be more hyper-vigilant about testing. This is why they continue to recommend multiple semen sample test.
With His Choice vasectomy you can be reassured your vasectomy has worked as intended if your 3 month semen sample show the absence of motile sperm.
Do you recommend yearly testing to detect late vasectomy failure?
No. If the first 3 month after vasectomy semen sample test shows no motile sperm we do not recommend repeat semen sample testing in the future. Why?
The chance of a late vasectomy failure is approximately 5 out of every 10,000 patients.
If we wanted to prevent these 5 vasectomy failures we would have to test all 10,000 patients yearly. This would require a lot of effort, create a lot of cost, and cause a lot of unnecessary anxiety.
Essentially, we would be putting 9,995 patients through a whole lot of hassle to possibly detect 5 vasectomy failures. If you were one of those 5 patients you would be appreciative we prevented a possible pregnancy. If you were one of the other 9,995 patients you would be frustrated by the unnecessary testing.
To make maters even more complicated, most late vasectomy failures have sperm amounts that are so low they are very difficult to detect even with a careful microscopic semen analysis test.
Even the most sophisticated sperm test using flow cytometry can only detect sperm down to a level of about 5,000 sperm per/mL. This means even using the best test in the entire world….a person could be walking around with about 3,000 living sperm per/mL and actually have a negative semen sample test!
Remember we said no birth control method is 100% effective…well the same is true for laboratory test. No testing method is 100% effective at detecting abnormal conditions.
Many experienced vasectomy providers have had patients with late vasectomy failures in which no sperm were detected on multiple microscopic semen sample tests but DNA evidence proved paternity of the patient.
Late failure is not common. A large number of test would be required to detect some of the late failures. These tests would also miss some patients who had failure of vasectomy. Some vasectomy failures can be missed by falsely reassuring microscopic semen sample testing.
Need more reassurance about late vasectomy failure?
We recommend you appreciate the fact you have chosen one of the most effective methods of permanent birth control the you choose to have a His Choice Vasectomy procedure.
Once your 3 month after vasectomy semen sample confirms absence of sperm you can relax knowing you are using a highly effective method for prevention of pregnancy.
- If you are a ‘glass half full’ type of person then you can comfortably rely on the fact you have a method that is 99.95% effective at long term prevention of pregnancy.
- If you are a ‘glass half empty’ type of person then you will obsess over a 0.05% chance of failure that may be difficult to detect and may not ever cause pregnancy.
If you are concerned about the possibility of late vasectomy failure then we recommend you use any of the commercially available over the counter after vasectomy testing kits.
A commonly available FDA approved home testing kit is SpermCheck vasectomy. This test can be ordered on Amazon and easily be performed in the privacy of your home.
If you have chose to have a His Choice vasectomy we want you to be reassured you have chosen one of the best and safest methods of permanent birth control.
