By Melanie Atkinson
Vasectomy offers non-reversible contraception to men but efficacy is not immediate and requires post-vasectomy semen testing (PVSA) to confirm success. Clearance to discontinue alternative contraception is given on a fresh semen sample with <100,000 non-motile sperm/mL. However, many men still fail to submit samples following a vasectomy, risking pregnancy by being unaware of their unsuccessful outcome.
In recent years, many vasectomy surgeons have recommended postal testing to increase access and acceptability to their patients. Due to time in transit and lack of temperature control, the motility of sperm in postal samples cannot be assessed. Therefore, clearance on postal testing may only be granted in the complete absence of sperm, and must form part of a strategy that also includes fresh testing, to allow clearance of men who repeatedly ejaculate small numbers of sperm.
A paper published in the FSRH journal in 2021 (Atkinson M, et al. BMJ Sex Reprod Health 2021;0:1–6. doi:10.1136/bmjsrh-2021-201064) provides evidence for a postal testing strategy. Data available from nearly 60,000 vasectomies showed no significant difference in early or late failure rates when a postal testing strategy was compared to fresh testing. Compliance was 20% higher with a postal testing strategy, allowing 1 more early failure to be detected for every 500 vasectomies completed. This postal testing strategy has been incorporated into the FSRH 2024 Vasectomy Service Standards, enabling both surgeons and patients a convenient means to evaluate surgical outcome.
While a postal testing strategy benefits vasectomy patients overall, for an individual choosing between taking a sample to their local laboratory or posting their pot in the local post box, which method can they safely rely on?
A new study published in 2025 (Atkinson M, et al. BMJ Sex Reprod Health 2025;0:1–7. doi:10.1136/bmjsrh-2025-202768) directly compares post-vasectomy semen samples analysed fresh (within 2 hours) and after 72 hours of transport to a postal laboratory. After testing, the remainder of the fresh sample was packaged and posted to the postal laboratory for analysis. The same protocol was followed by each laboratory, and 25 µL aliquots were examined in 100µm CellVision counting chambers, and the entire slide was counted or estimated if >100,000/mL.
Semen samples were submitted at 12 weeks post-vasectomy and 197 paired samples were studied. 94.9% of men were given clearance to discontinue additional contraception on the first PVSA, when the current guidance, <100,000 non-motile sperm/mL on fresh testing, was applied. 6 men (3%) received clearance after submitting further samples. There were 3 men with presumed recanalisation whose samples showed motile sperm on first PVSA, including one with motile sperm noted in the postal sample. All showed a sperm concentration >100,000 sperm/mL and would have been identified by the postal testing strategy pathway as requiring additional testing.
A Bland Altman plot showed high agreement between sperm concentrations of both fresh and postal PVSA. When sperm concentration ranges were compared, the only statistically significant difference was when ‘no sperm seen’ results were compared. False negatives (no sperm seen) were observed in both fresh and postal paired samples, but this was expected due to the high level of counting error at very low concentrations (Cooper TG, Hellenkemper B, Jonckheere J, et al. Azoospermia: virtual reality or possible to quantify? J Androl 2006;27:483–90). Diagnostic test characteristics of postal PVSA showed excellent sensitivity and specificity at all sperm concentration cut-offs above 1000 sperm/mL.
We can be reassured about postal testing, as sperm concentrations reported compare favourably with fresh testing. However, it is important to remember that confirmation of vasectomy success on postal testing currently requires no sperm to be seen. Is this level of stringency truly necessary, or could clearance be safely given in the presence of very small numbers of sperm? The 2025 study shows that the likelihood of falsely giving clearance on postal PVSA samples showing ≤5000 or ≤10 000 sperm/mL is minimal, as the negative predictive values at these cut-off values are 99%. The likelihood of finding motile sperm at such low concentrations is negligible (Labrecque M, Hays M, Chen- Mok M, et al. Frequency and patterns of early recanalization after vasectomy. BMC Urol 2006;6:25).
If we apply the 59% compliance to fresh testing from the 2021 study and apply our 95% clearance rate, just 56% of our vasectomy patients could be reassured of vasectomy success. However, if we take the 80% compliance to postal testing from the same study and award clearance at ≤10 000sperm/mL, 73% of men would be cleared on first testing at 12 weeks! A win-win situation!
We should therefore review current guidelines to allow both patients and surgeons to make full use of a safe and inexpensive method for confirming vasectomy success. Men who have undergone a procedure to curtail their fertility should be aware of the outcome as soon as possible and not be left waiting months to submit a fresh sample due to lack of appointment availability. If fewer fresh PVSAs were performed, it would also free up more slots for subfertile couples.
The benefits of postal testing appear to far outweigh the risks, while also removing several barriers to assessment. When incorporated into a postal testing strategy, this approach allows all men to access their vasectomy outcome conveniently and with confidence.
About the Author
I graduated from Nottingham University and completed training in General Practice but decided to concentrate on Contraception & Sexual Health, training in no scalpel vasectomy in 2001. From 2011 onwards vasectomy provision and training became my sole role until retirement from clinical work in 2024. I was joint training lead for the Association of Surgeons in Primary Care (ASPC) who have honed my writing skills, publishing papers, writing service standards and other documents for the Faculty of Sexual and Reproductive Health. Last year I was privileged to train doctors in Zambia on behalf of World Vasectomy Day, my career highlight.