Post-Vasectomy Semen Specimens
Post-vasectomy sperm checks are usually performed on at least two specimens collected at the time intervals defined by the patient's physician. Two successive specimens that are totally absent of motile and non-motile sperm are ideally required to verify the absence of sperm after vasectomy.
The American Urological Association (AUA) post-vasectomy guideline published in 2012 has these recommendations:
- Report both the presence and absence of sperm and presence or absence of sperm motility on the patient report.
- If no sperm are seen in the uncentrifuged specimen, report that the presence of sperm is below the limit of detection.
- Do not centrifuge the specimen for further assessment; centrifugation can negatively affect motility.
A semen specimen received for routine semen analysis that apparently has no sperm present when it is examined microscopically can, for most clinical purposes, be reported as <2 x 106 /mL. If it is necessary to document the absence of sperm, the sample must be re-evaluated after the specimen has been concentrated. Concentration is accomplished by centrifuging a 1 mL aliquot of the well-mixed specimen at 3000G for 15 minutes. The concentrated portion (sediment) of the sample is then examined by placing a drop of the sediment on each of two slides and systematically observing the entire coverslipped area of both slides. If no sperm are seen on the concentrated sample a report of "no sperm seen on a concentrated sample" can be made. The absence of sperm suggests a diagnosis of azoospermia.