What is diagnostic semen analysis?

Semen analysis is the gold-standard test performed to assess the fertility potential of a male. Several important parameters are measured which include semen volume, sperm concentration, sperm motility and sperm shape. All parameters are compared to reference ranges set by the World Health Organisation (WHO).

The total number of spermatozoa per ejaculate, sperm concentration and the extent of progressive sperm motility are related to pregnancy rates. Motility assessment is usually performed using computer-aided sperm analysis (CASA).

What is a post-vasectomy semen analysis?

Approximately 12 weeks after your operation you are required to produce a semen sample to confirm whether your vasectomy has been successful. During the analysis we will not only check for the presence of sperm but also whether any sperm seen are motile and have fertilisation potential.

Some sperm can remain in the vas deferens in the months following your procedure. It is important that you have ejaculated (via masturbation or with contraception) over 20 times before your post-vasectomy semen analysis to help clear out any sperm that have remained.

How do I get an appointment?

Once you have been referred to us by a clinician you will be able to book in for your appointment online using the NHS e-Referral service. After you have booked in, we will send you out a pack to the address provided to us. This pack will contain instructions, a production form and sample pot. These instructions must be read in advance of your appointment. Appointments are available Monday to Friday.

  1. The NHS e-Referral service is not currently in place for Leighton hospital so a specific appointment date and time will be sent out to you in the post.

We are unable to accept any samples without an appointment.

I have been sent an appointment, do you have any directions?

The Hewitt Fertility Centre, Liverpool Women’s Hospital (L8 7SS)

The Lewis-Jones Andrology Department at the Liverpool Women’s Hospital is situated on the second floor. Please follow signs for the Hewitt Fertility Centre and our waiting room is situated next door. Appointments for diagnostic semen analysis and post-vasectomy semen analysis are available Monday to Friday.

The Hewitt Fertility Centre, Knutsford (WA16 8ZR)

The Andrology laboratory is situated on the ground floor. Upon arrival please report to reception and a member of staff will be able to assist you. Please note we are only able to offer appointments for post-vasectomy semen analysis on Tuesdays. Please feel free to contact us to find out the dates that these sessions are being held.

Ormskirk District General Hospital (L39 2AZ)

The Seminology laboratory is located within the Gynaecology and Maternity department. From the main entrance of the hospital please continue two thirds of the way up through the main corridor and turn right. Please note we are only able to offer appointments on Mondays. Please feel free to contact us to find out the dates that these sessions are being held.

Leighton District General Hospital (CW1 4QJ)

The Andrology Laboratory is situated on the 2nd floor (Ward 25) of Leighton Hospital. From the main entrance of the hospital proceed through the Antenatal Clinic entrance, take the stairs to the 2nd floor and follow signs to Ward 25. Please note we only offer appointments here on Fridays.

How should I produce the sample?

Samples should be collected by masturbation. Do not produce your sample using lubricants, condoms or through the withdrawal method. If you are unable to ejaculate by masturbation, special condoms for use at home may be provided in exceptional circumstances. However, the entire ejaculate will not be available for examination, and the specimen is likely to be contaminated by contact with the skin of the penis and to some extent also vaginal fluid and cells on the outside of the condom.

Are there instructions for collecting the sample?

In order to obtain an optimum sample you are required to abstain from any sexual activity (masturbation or intercourse) before your appointment. Please ejaculate 4 days before your appointment and then again 2 days before your appointment. Do not ejaculate again until you are producing your sample for analysis.

Produce your sample by masturbation into the non-toxic sterile pot provided in your pack. Your pot must be labelled with your name, DOB and hospital identification number.

Please do not attempt to produce your sample into any other type of specimen pot.

Please ensure you attempt to collect all of the semen produced.

Once the sample has been collected please ensure the lid is screwed on tightly and place the pot inside the sealable bag provided.

Ensure you bring the fully completed request form with you to the hospital. We cannot accept your sample until this has been completed correctly.

The pot must not be exposed to extremes of temperature either before or after sample production. If you are concerned about this, please speak to a member of staff.

Where can I produce the sample?

You may produce your sample at home if you can deliver it to the laboratory at your allotted appointment time preferably within 30 minutes after collection and at least no longer than 50 minutes after collection. Whilst travelling from home it is important you keep the sample close to the body under clothes during transportation (for example, in a pocket) as sperm are sensitive to extremes of temperature. If preferable, your partner may deliver your sample and completed production form.

If you cannot deliver your sample to the laboratory within 50 minutes of ejaculation or would rather produce your sample on site, we have private, sound-proof production rooms available for use.

How do I get my results?

Your results will be sent back to your referring clinician approximately 14 days after your semen analysis. If you have had a vasectomy you should continue to use an alternative method of contraception until you have received confirmation of the success of your vasectomy, also known as clearance. Unfortunately, results cannot be given to you by our laboratory staff.

Repeat tests

If you cannot produce your sample or have an incomplete collection you may be asked to repeat the test after a further 2 days abstinence. If one or more of your sperm parameters are reported below the lower fifth percentile (WHO 2021) your clinician may request you repeat the test. This is to ensure your results are representative of a typical ejaculate.

What if I have a poor result?

Discovering you have a poor result may come as a shock and leave you feeling anxious. We have counsellors and patient support groups available at our Liverpool and Knutsford centres if you would like to discuss your feelings relating to this diagnosis.

You should always bear in mind that advances in fertility treatment mean that you may still be able to conceive. You can discuss your options and next steps with your clinician.

I have had a vasectomy but you have found sperm. Does this mean it hasn’t worked?

If you have not ejaculated 20 times or it has not been 12 weeks since the operation you may be asked to repeat the test at a later date. You may also be asked to repeat the test if there are any sperm seen in your sample.

The presence of sperm doesn’t necessarily mean your vasectomy has been unsuccessful since some sperm may remain in the vas deferens for a while after the operation. If invited, it is important that you attend your repeat test as it will help to confirm whether all remaining sperm have been cleared out of the vas deferens.

It is important to know that clearance is only given to patients when the clinician can be sure that they could not achieve a pregnancy. If you fail to attend your post-vasectomy semen analysis or discontinue the use of contraception, this could result in an unplanned pregnancy. You must continue to use an alternative form of contraception until you have been granted clearance by your surgeon.

Research and waste

The portion of your sample that is left over after diagnostic semen analysis is disposed of by incineration. It will not be stored for treatment purposes. In some cases, it may be used by us for training or research.


Please feel free to contact the laboratory on 0151 702 4214 if you require any further information about this test.


The Lewis-Jones Andrology department at the Hewitt Fertility Centre has provided a dedicated Andrology service for over 10 years. We were the first Andrology laboratory to be accredited for quality and competence by the UK Accreditation Scheme (UKAS). Our laboratory is also enrolled in the UK National External Quality Assurance Scheme (UK NEQAS) which helps to ensure clinical laboratory test results are accurate, reliable and comparable wherever they are produced.

I am a GP or clinician and I would like to refer a patient to your services. How do I do this?

GPs and other clinicians please follow this link to find information on how to refer patients to our services.