By Dr. Melanie Atkinson
Vasectomy offers non-reversible contraception to men but efficacy is not immediate and requires examination of a semen sample post-vasectomy to confirm successful occlusion of the vasa deferentia so that other methods of contraception can be discontinued. This post-vasectomy semen analysis (PVSA) was, in the past, always completed on fresh specimens examined at the local laboratory within an hour or two of production. It was recommended by the Faculty of Sexual and Reproductive Healthcare (FRSH) until 2014 that two fresh semen samples, showing no sperm, were required for the vasectomy to be considered a success. This was amended however in 2014, in line with earlier American Urological Association and European Association of Urologists Guidelines, to just one sperm free semen sample. These later FSRH guidelines also recommended that vasectomy can also be considered successful if there are small numbers of non-motile sperm present – prior to 2014 this figure was <10,000, and subsequently <100,000 – without any increase in pregnancy rate. Although the criteria for clearance are more easily met now, still many men having vasectomies fail to complete the process by submitting semen samples and would be unaware if their vasectomy had failed until a pregnancy ensued.
In later years, increasing numbers of surgeons have chosen to recommend a postal method for submission of PVSA which has the advantage of being easily accessible to all patients. Though this is considered acceptable by the Royal College of Obstetrics and Gynaecology and the American Urological Association, it is not recommended by the Association of Biomedical Andrologists (ABA), the British Andrology Society (BAS) and the British Association of Urological Surgeons (BAUS).
The Association of Surgeons in Primary Care undertakes an annual audit and a total of 90 surgeons provided data on 71,112 vasectomies over an 11-year period. Of these, 58,900 vasectomies were included in our study, comparing compliance with testing and failure rates for non-postal local laboratory testing of fresh specimens and postal testing, which by definition could not be on a fresh specimen. The disadvantage of postal testing is that if small numbers of non-motile sperm are seen (<100,000), clearance cannot be given as it is unknown whether or not they would have been motile had the specimen been examined sooner. In these circumstances postal testing can be repeated or a fresh specimen can be submitted to the local laboratory.
Overall, the proportion of men who had had a vasectomy and fully complied with semen analysis was 20.4% higher (79.5% v 59.1%) with postal testing than non-postal testing, enabling 1 in 5 more men to receive clearance to stop using other methods of contraception. The early failure (motile sperm seen on PVSA) rate for postal testing was slightly lower, as was the late failure (pregnancy after successful vasectomy) rate. However only the difference in early failure rates was statistically significant (0.73% v 0.94%).
When analysis is limited to vasectomies performed after the change in FRSH guidelines to those currently in place, the differences between the two testing strategies are still present. The absolute difference for compliance was 18.6% in favour of postal testing (79.7% v 61.1%), whilst both early and late failure rates were not significantly different.
We believe this is the first study comparing compliance for postal and non-postal strategies for semen testing and it is robust due to sample size and time span. Our results have major implications. Due to better compliance, surgeons can detect more early vasectomy failures if they elect to use postal testing. Assuming a similar 1% early failure rate for both strategies, with 20% higher compliance for postal testing, 1 more early failure will be detected per 500 vasectomies (number-needed-to-be-tested). If the calculation is repeated with the data reflecting the current one-test guidance practice in recent years, the higher compliance of postal strategy still allows detection of 1 more failure in 833 vasectomies.
ABA/BAS/BAUS have questioned the validity of postal semen testing, suggesting sperm degradation during transit resulting in wrongly awarded clearance. Although a direct comparison of semen samples examined by both semen sample submission strategies could be undertaken to justify this statement, the similarity of both strategies on early and late failure rates in our study suggests that this concern should be refuted.
A disadvantage of postal testing is that fresh non-postal testing at the local laboratory is required if early failure is suspected because non-motile (rarely motile) sperm are seen on postal testing. However, a recent study on 5,965 first fresh semen samples post-vasectomy demonstrated that if the non-motile sperm concentration is below 10,000 sperm/mL or below 100,000 sperm/mL, the probability of observing motile sperm is 0.7% and 0.9%, respectively.
Our study has some limitations, primarily in that many different surgeons submitted data, with varying experience, different techniques and alternative clearance/failure criteria. The time schedule for testing and reminders influences compliance as does proximity and availability of suitable appointments at the local laboratory. However, we do not believe this would change our conclusions considering the scale of the difference in compliance.
Postal semen sample submission is not only a less resource intensive approach, but is clearly more acceptable to patients. The higher compliance of postal strategy confers overarching benefits to patients, their partners, and surgeons seeking confirmation of vasectomy success, without compromising efficacy to detect failures. Our study should reassure both surgeons and patients who presently use postal semen sample submission strategy. It may also inspire more surgeons, commissioners and laboratories to follow this approach. Future clinical practice guidelines should recommend submitting semen samples by post as a reliable option.
Read more: Comparison of postal and non-postal post-vasectomy semen sample submission strategies on compliance and failures: an 11-year analysis of the audit database of the Association of Surgeons in Primary Care of the UK
Dr Melanie Atkinson, formerly providing vasectomy services and training in Nottinghamshire and the Midlands, is now working as a Vasectomy Surgeon for the Aneurin Bevan University Health Board, South Wales.