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 absent of motile and non-motile sperm are ideally required to verify the absence of sperm after a vasectomy.
The American Urological Association (AUA) post-vasectomy guideline published in 2012 has these recommendations:
- Report both the presence and absence of sperm and the 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 with 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 the 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.