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Post vasectomy semen analysis – Information for patients

Patient information A-Z

CIVF logo - A purple and blue logo that reads 'Cambridge IVF, creating your future. ISO 9001 Quality Management.
Cambridge IVF, in top left is a man looking through microscope, top right a building with glass windows, bottom left close up of a microscope, bottom right hand holding a test tube in a machine.


Semen testing to confirm the absence of sperm in your semen (azoospermia) following vasectomy is an absolutely essential part of the process. This is why you have been asked to produce a semen sample for testing at Cambridge IVF or Ipswich IVF following your vasectomy procedure.

This process enables your doctor to confirm that the vasectomy procedure has been successful. You will need to produce more than one sample over a period of time to ensure that sperm do not start to appear again in your semen sample.

Semen analysis is the examination of your semen using a microscope to determine in your case whether or not sperm are present to allow us to confirm if your vasectomy procedure has been successful.

What do I have to do?

Firstly, you need to ensure that your doctor has provided you with a completed semen analysis referral form clearly indicating a request for a post vasectomy semen analysis. You can produce your sample at Cambridge IVF in Trumpington or Ipswich IVF in Ipswich, both labs work together to deliver the service. We do not recommend the production of post vasectomy samples at home. We will provide you with a suitable sterile container when you arrive. We will only accept samples produced into our own containers as we know these are fit for purpose and will not compromise the quality of the sample or harm any sperm we do find in any way.

Secondly, you need to ensure that your sample is produced no earlier than 12 weeks post vasectomy and you have ejaculated no less than 20 times following your vasectomy. These measures are in place to ensure that we are as likely as possible to be able to give you clearance post vasectomy with as little inconvenience to you as possible. If you do not meet these criteria when you attend for your sample we will need to repeat your test.

Finally, you need to telephone the Andrology Service on 01223 349010 (option 2) and arrange your appointment to produce your sample for analysis no less than 12 weeks following your vasectomy.

Please note there may be a wait of up to four weeks before we are able to offer you an appointment but we will do our utmost to accommodate you as soon as possible.

In order to get the best sample from you we require you to abstain from any sexual activity (including masturbation) for between 2 and 5 days (but in no case more than seven days) prior to your appointment date.

In both Cambridge and Ipswich we have quiet and discrete rooms available for you in which you can produce your sample.

Normal Opening Hours

Our opening hours are as follows:

Cambridge Laboratory Ipswich Laboratory
Monday Cambridge Laboratory 08:00 – 16:00 Ipswich Laboratory 09:00 – 15:30
Tuesday Cambridge Laboratory 08:00 – 18:00 Ipswich Laboratory 09:00 – 15:30
Wednesday Cambridge Laboratory 08:00 – 16:00 Ipswich Laboratory 09:00 – 15:30
Thursday Cambridge Laboratory 08:00 – 18:00 Ipswich Laboratory 09:00 – 15:30
Friday Cambridge Laboratory 08:00 – 16:00 Ipswich Laboratory Closed
Saturday Cambridge Laboratory Closed Ipswich Laboratory Closed
Sunday Cambridge Laboratory Closed Ipswich Laboratory Closed

Cambridge IVF does not operate a sample ‘drop in service’ at either laboratory as semen analysis is a time critical test and specimens must be produced and analysed at appropriate and pre-arranged times. If you arrive more than 30 minutes after your allocated appointment time or do not have your referral form with you, we will be unable to perform your test and you may have to re-book the appointment. You should therefore give yourself plenty of time to arrive, especially if travelling by car. We do have ample free parking onsite in Cambridge but the roads surrounding Cambridge can sometimes be unexpectedly congested. In Ipswich the most convenient car park is Car Park ‘G’ which is pay and display. If you cannot keep your appointment time for any reason please call and we will re-book your appointment for the next mutually convenient time and date.

How do I collect the sample?

Samples are either produced on site at in one of our dedicated sample rooms. Although our rooms are well proportioned we suggest that you produce your sample on your own; we do not recommend your partner accompanies you into the room although they are very welcome to wait for you in our waiting area.

  • Firstly ensure that you have booked an appointment time
  • Ensure that you have been provided with a completed semen analysis request form from your doctor and they have indicated the test required is a post vasectomy semen analysis. Your form should have your name, date of birth, NHS number, partner’s name, partner’s date of birth (if applicable) and the date on which your vasectomy was performed
  • Abstain from any sexual activity for 2 to 5 days but for no more than seven
  • At your allocated appointment time a member of our laboratory team will greet you from the waiting area, check your referral form is completed correctly and provide you with an appropriately labelled sample container. We will then show you to the private sample room in which you can produce your sample
  • Thoroughly wash, rinse and dry your penis, testicles and hands before you produce the sample
  • If producing on site, masturbate and collect the sample into the container making sure you tightly cap it
    • In Cambridge, place it in the hatch to the laboratory (along with your completed referral form). Close the hatch and press the switch to let the lab team know your sample is ready for collection.
    • In Ipswich, place the sample in the provided sample tray and leave as instructed in the sample room with your completed referral form. Press the ‘doorbell’ and leave; the lab team will collect your sample from the production room.
  • Complete the bottom part of the referral form: we need this information to ensure we get as much accurate information from your semen analysis as possible. If any of this information is missing we will not be able to accept the sample so it is very important that you take the time to check it is completed correctly
  • Inform us if any of the sample is missed during production. Most of the sperm in the ejaculate are contained in the first part. If you do miss some of the sample we may ask you to repeat the test to ensure an accurate result can be provided to your referring doctor. Despite the fact we are aiming to find no sperm in your sample post vasectomy it is still essential we have a complete sample to work with as it is possible sperm may be present in the part of the sample which was missed, particularly if this was the first part. Be honest when completing the sample form, it is much better to repeat the test and be sure than get an inaccurate result.
Semen production room - a chair and foot stool, a small table and a television mounted on the wall.

Our production rooms have been designed to be comfortable and private and a video system is available to you should you wish to use it. In Cambridge, a hatch system links each room directly to the laboratory to allow easy delivery of your sample. In Ipswich a ‘doorbell’ system is in use to inform the lab when your sample is ready. Further site-specific instructions will be given to you by our team before you produce the sample at your chosen location.

Please note that masturbation is the only recommended method for collecting the sample ‘cleanly’ for analysis. The withdrawal method is not recommended as it is likely that some of the sample will be lost and may in any case be contaminated. The first part of the ejaculate contains most of the sperm so this is particularly important. Ordinary condoms cannot be used as these contain a spermicide which will kill any sperm in the ejaculate.

If you have any problems producing your sample or need to change an appointment please give us a call, we will happily arrange another appointment for you.

How will my sample be tested?

Current best practice for post vasectomy semen analysis (PVSA) has recently been updated. We are now able to clear men on the basis of a single sample where the sample production criteria are stringently adhered to. This is why we no longer accept PVSA samples produced at home. We will assess your sample using a procedure called ‘large volume assessment’ to determine the presence or absence of sperm and carry out the following routine tests as part of your semen analysis:

Sperm volume

We record the actual volume in millilitres of the semen sample you provided. We do not expect you to fill the container; an average ejaculate will be around 2.5 ml but some men will produce more or less semen.

Sperm concentration (sperm count)

Reported as millions per millilitre of semen. We use a microscope to identify if sperm are and if any are, we count the number of sperm in the sample using a special counting chamber and report this finding to your doctor.

Sperm motility

If sperm are present in the sample, the sperm are grouped into four groups with the strongest swimmers (grade ‘a’) being the most fertile. If there are any motile sperm in your sample we cannot grant you clearance as just a single motile sperm could fertilise an egg.

Sample centrifugation

In some circumstances we may also load the whole sample into a test tube and spin it in a machine called a centrifuge which causes any cells in the sample (including sperm) to form a concentrated ‘pellet’ in the bottom of the tube. This can then be harvested and examined under the microscope to confirm whether or not there are sperm present in your sample.

How will I get my results?

A written report will be sent to your referring doctor within 10 working days of your test appointment. Try not to become too anxious if your GP is unable to answer all of your questions, it may be that they need to contact Cambridge IVF for more information or advice. For reasons of confidentiality we will never give out results over the telephone so please understand the good reasons why any such request will be politely declined.

How do I know when my sample is clear?

Clearance post vasectomy is defined as follows:

  • One ‘azoospermic’ semen sample (a sample with no sperm in the ejaculate) produced according to our defined sample production criteria at least 12 weeks and 20 ejaculations post vasectomy.

If your sample meets these criteria you will be granted clearance to stop using other forms of contraception. If sperm are identified in your sample you will be asked to repeat the test 4 weeks later and should book another appointment accordingly.

There are still sperm in my sample(s), what does this mean?

Persistent non moving (immotile) sperm can remain in semen for several reasons and your doctor will explain what they believe is the reason for this to you. ‘Special clearance’ can be granted by your doctor in such cases where a concentration of less than 100,000 immotile sperm remains following the analysis of 2 semen samples produced at least 4 weeks apart.

Cambridge IVF cannot be held accountable where clearance has been granted in such circumstances and a patient then goes on to form a pregnancy.

Our commitment to quality in our service

The laboratory team at Cambridge IVF have a combined experience of over 40 years in performing the range of tests which in combination provide a complete and accurate semen analysis. All tests are performed in accordance with the guidance set out by the World Health Organisation (WHO) and the Association of Reproductive and Clinical Scientists (ARCS). The laboratory subscribes to the National External Quality Assurance Scheme (UKNEQAS) for Reproductive Science.

Queries or complaints

If you have any questions regarding any part of the Andrology Service provided by Cambridge IVF please do not hesitate to contact us using any of the contact details on the back of this information at any time between the hours of 08:30 and 16:30. If you are unhappy with any part of the service or wish to speak to someone about an issue relating to your care please contact our lead clinical scientist or if you prefer, the Patient Liaison Service (PALS) at Addenbrooke’s Hospital, who you can reach by emailing PALS or telephoning extension 2756 at Addenbrooke’s Hospital.

Finding Cambridge IVF in Trumpington

Please note that Cambridge IVF is not located on the main CUH Campus.

We are very easy to access by car, public transport and bicycle. When approaching from Trumpington Road, look out for Bidwells Estate Agent (next to the Shell garage) on the corner of Maris Lane. Kefford House is immediately behind this complex of buildings and shares a car park with them.

Getting here by car

The clinic is just off Trumpington Road, easily accessible from the M11 and A11 if coming from outside Cambridge. There is plenty of free parking at the centre indicated by yellow parking bays marked with a ‘K’. It is important that you use these parking spaces and not the others which are allocated to other buildings. You can also park at the Trumpington Park and Ride and take a bus. There is a stop close to the centre on Trumpington Road (see below).

Cycling to Cambridge IVF

There is ample covered cycle racking provided directly outside of Cambridge IVF for those wishing to cycle.

Public transport – Getting to Cambridge IVF by bus

Please visit Stagecoach - plan a journey (opens in a new tab) to plan your journey.

Finding us map

Finding Cambridge IVF at Ipswich Hospital

The Cambridge IVF Andrology Service is located in the Central Zone, in the Gynaecology Clinic on the 1st floor. This is clearly signposted. A map of the hospital is available on the East Suffolk and North Essex NHS 'get to Ipswich hospital' page (opens in a new tab).

Getting here by car

The address for Ipswich Hospital is: Heath Road Ipswich Suffolk IP4 5PD.

Please park in car park G. Please note that parking charges apply (pay and display).

Your appointment should not last longer than one hour.

Public transport

Please visit the East Suffolk and North Essex NHS Foundation Trust website (opens in a new tab) for more information on finding your way as well as information about how to get the hospital by public transport.

If you require any further information regarding the clinic and available treatments please contact us on 01223 349010 or e-mail Cambridge IVF.

Visit the Cambridge IVF website (opens in a new tab).

We are smoke-free

Smoking is not allowed anywhere on the hospital campus. For advice and support in quitting, contact your GP or the free NHS stop smoking helpline on 0800 169 0 169.

Other formats

Help accessing this information in other formats is available. To find out more about the services we provide, please visit our patient information help page (see link below) or telephone 01223 256998.

Contact us

Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151