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Post Vasectomy Semen Analysis Service

Cellular Pathology

Principle of Examination

Vasectomy is a safe and effective method of contraception for men. Post vasectomy semen analysis (PVSA) is recommended to confirm clearance of stored spermatozoa and also to identify rare cases of early recanalization or technical failure. Sterility is usually confirmed after a single post vasectomy seminal fluid is clear of spermatozoa. However if spermatozoa are present a second sample must be provided to the lab within 1 hour of production to assess motility. If sperm are present in the second sample a third sample may be recommended which will be sent to a suitable clinic specialising in reproductive medicine.

Sperm motility will be reported in specimens received within 4 hours of sample production, where motile or non-motile spermatozoa are identified in the initial sample preparation.

Spermatozoa motility will not be reported by the laboratory if spermatozoa are only identified in the centrifugate preparation. This is due to the centrifugation process, which may result in previously motile spermatozoa being rendered non-motile. In these instances  the report will state ‘spermatozoa present’ with no comment on motility. It is recommended that these patients provide a second sample to the laboratory within 1 hour of production to assess motility.


Interpretation & Advisory Service for PVSA

For further advice and result interpretation please contact:

Dr Mark Watson (MBChB, MRCGP, DRCOG, GPxSI (vasectomy), Trainer in Vasectomy under LA) at St Thomas Health Centre, Exeter on 01392 676676.

Specimen Requirements

PVSA samples can either be requested via GPOCS or using a request form.

Specimens suspected or known to have Covid-19 will not be processed at this time as an unfixed wet preparation is required to make an accurate assessment for the presence of spermatozoa. 

  • Patients are usually asked to provide a post vasectomy sample, a minimum of 12 weeks after surgery and after a minimum of 20 ejaculations.  A second sample may be required for persistent spermatozoa and may be sent to a clinic specialising in reproductive medicine for full analysis.
  • The laboratory will supply the practitioner (or patient) with a 50ml toxicity tested specimen container, a carrying box and a request form. To obtain these kits please contact Pathology Stores on 01392 402906.
  • The entire seminal fluid sample must be collected – see ‘Instructions to patients. . .’ below, a toxicity tested specimen container MUST be used.

Instructions to patients for collection of seminal fluid for post vasectomy analysis.

1.  You should have a toxicity tested specimen container and pathology request form for each sample. You MUST complete the form with the date and time of sample collection and if the entire sample was collected

1. The container provided MUST be labelled with your FULL NAME, DOB and the DATE and TIME of collection. Unlabelled specimens will not be accepted, so please make sure that the specimen is clearly identified.

2.    It is best to abstain from intercourse for 2 – 7 days before producing a specimen. The specimen should ideally be collected in the morning and kept as close to body temperature as possible during transport. – Do NOT refrigerate.

3.    The semen must be passed directly into the container provided.  It must be collected by hand ONLY. Do not use lubricants or condoms as they will kill sperm. The complete sample must be submitted.

4.    After collection, replace the screw cap firmly on the container.

5.    The specimen should arrive labelled in the laboratory as soon as possible after production, preferably within 4 hours, together with the pathology request form (specimens are not accepted on Saturdays or Sundays).

**If your GP has requested that you bring a sample to the laboratory within 1 hour of production, please contact pathology reception on (01392 402913) and inform them of the expected date and time of specimen delivery**

6.    Deliver the specimen and completed request form to the:

Cytology Department
Pathology Block
Royal Devon & Exeter Hospital (Wonford)
Church Lane
EX2 5AD                         (Directions below)

Please deliver the sample and request form to the Pathology Reception main entrance. Do not post the specimen.

The results of your test will be sent to your doctor.

The Laboratory aims to comply with The royal College of Pathologists Key performance Indicator (KPI 6.4) for Cellular Pathology reporting turnaround times with 90% of all cases reported within 10 calendar days.

The Laboratory Limit of Detection (LOD) for spermatozoa is available – please contact the laboratory.



1.    Travelling along Barrack Road From Topsham Road, go through the traffic lights, pass the hospital main entrance on your right, pass a second entrance to the hospital on the right, and then take the next right turning into Church Lane.

2.   Take the 2nd right turn into the hospital grounds. The Pathology building is the concrete grey 4-storey building on the far left.


Approaching from the city centre, from Heavitree Road turn right at the traffic lights into Barrack Road, go through the next traffic lights and take the next left into Church Lane.  (Then see “2” above)


Specimen Labelling Procedure
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