The Cleveland Clinic in the US has just published a study on the effectiveness of vasectomies irrespective of subsequent partner's pregnancy. They find that vasectomy is 99.85% effective based on sperm count several months after the procedure. As long as sperm is present, pregnancy is possible and they found several cases of sperm presence a month or more after the vasectomy. Could be sperm that have been hiding in the prostate and it takes a few ejaculations to get it out. Some continue to hide and show up later.

After a vasectomy, do not assume you are safe! You should have at least two sperm counts reading zero (for both live and dead sperm) before stopping other forms of contraception.

Posted: 28 Sep 08:25