Semen Analysis after your Vasectomy is important to do as it signs off on the vasectomy being effective for contraceptive purposes. It may cause a little confusion for some people though and I have tried to clarify it below.
The postal address for the semen sample is; Microbiology Department, Rotunda Hospital, Parnell Square, Dublin 1
The earliest time we do a semen analysis following a vasectomy is 12 weeks after the procedure. The current guidelines also recommend that at least 25 ejaculations have occurred over this time period. Both numbers are important. We ask you to do the sample at home and post it to the Rotunda in the pot/container provided. The reason you can post it is because this sample is not “time sensitive”. I’m only interested in finding out if sperm are present or not present and this means that it is not “time sensitive”, so it can be posted.
95% of men will have a clear sample on the first sample (no sperm present, meaning the vasectomy was successful). If this first sample is clear then you can start relying on your vasectomy for contraception.
Of the group who have sperm present in the first sample a further sample is repeated a few weeks later. At this stage nearly 100% of men will produce a clear sample after a vasectomy and you can then start using your vasectomy for contraception.
Approximately 1 – 2% of patients that have had a vasectomy will have persisting sperm in the first 2 samples. In these cases a detailed sample needs to be performed to ensure that any sperm present are dead sperm. This sample has to be delivered to the Rotunda within 90 minutes of producing it, or do it in the Rotunda itself as this sample is “time sensitive”.
If any sperm are still present we examine them for movement and for numbers present. If the sperm are not moving (dead sperm) and if they are in small numbers (<100,00/ml) then your vasectomy is as effective as having no sperm at all. This is called “special clearance”. The reason for this is because some men who have a vasectomy have randomly occurring sperm in the seminal fluid. This is a situation called “Random Non-motile Sperm”. This does not mean your vasectomy has not worked and this may occur regardless of what method (clips, ties, sutures, no-scalpel or conventional vasectomy) is used to do your vasectomy. What is happening is that “dead sperm” are appearing in the seminal fluid and the presence of them makes your vasectomy as effective as a sample without any sperm present.
Even if you had more than 100,000 sperm per ml present, and they are dead sperm, your vasectomy would be more effective than any other form of contraception available today. However, the guidelines say we should accept <100,000/ml as the cut off for dead sperm that are acceptable so that’s what we do.