Your guide to vasectomies

18 January 2019, Tim Burton

Vasectomies are a form of surgical contraception that involves cutting and tying the tubes that deliver sperm from the testicles. It is a relatively straightforward procedure, but it’s common to have a lot of questions, so here’s a quick guide for you and your partner.

How it works

Without going too far back to cringey PHSE classes at school, here’s a little summary of how vasectomies avoid pregnancy.

A woman become pregnant when sperm reaches her egg. Vasectomies work by stopping sperm from ever leaving the testicles. There are small tubes (called vas deferens) that carry sperm from the testicles, up to the prostate, and out through the penis.

A vasectomy means these tubes are cut and tied, meaning the sperm never makes it out of the testicles, which inevitably means that pregnancy is not possible when a couple has unprotected sex.

After the operation, a man will still ejaculate semen, as most semen is not produced by the testicles, but by the prostate. Only around 5% of semen is made up of sperm, the remaining 95% is seminal fluid from the prostate. After the vasectomy, ejaculation will appear the same as before.

The benefits

  • Effectiveness: If you are sure you do not want any (more) children then a vasectomy is a good way of almost completely ruling out that option. According to the NHS, a vasectomy is more than 99% effective.
  • Sex drive: The operation does not stop the testicles from producing testosterone, so it has no effect on a man’s sex drive

What you should know

  • It is normal to feel uncomfortable for a day or two after the operation, but mild painkillers will help. Your doctor may well advise you to take it easy for a few days to avoid inflammation.
  • Vasectomies do not make you instantly sterile. It will take 25-30 ejaculations over the next two months before your sperm count reaches zero. You will have to provide sperm samples for testing so that you can be sure there is no sperm present. Until you have had confirmation that no sperm is present, you should continue to use other forms of contraception
  • You will have to wear tight fitting, supporting underwear for a few days after the operation so that your scrotum will remain supported. This should ease the discomfort and limit swelling
  • You can have sex again as soon as it is comfortable for you to do so

Reversing a vasectomy

It is possible to reverse a vasectomy, but the success of the operation will depend on how long it has been since you had the initial vasectomy. The NHS says that the success rate of reversing a vasectomy is about 55% in the first 10 years after the initial operation. However, that figure drops to 25% if it has been more than 10 years.

Because it is not always possible to reverse a vasectomy, you should make sure you are absolute certain that you want a vasectomy before you have the operation.


If you would like to know more about vasectomies, take a look at our Urology Health page.


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