A few weeks ago, I asked people to tell me their experience with IUDs without having been pregnant. I had one inserted the last week and so far so good!

Like most of you said, the insertion wasn't that bad - it cramped, but it was fine, and nothing some advil and a hot pad couldn't fix.


However, I was talking to a friend who's studying to be a sexologist, and told her that I was getting one. She immediately exclaimed "Oh, non-hormonal IUDs are not good, only 70% effective. If you want the 99% effective you have to get the Mirena" ... I told her that NONE of the stuff I had read said that the copper IUD was anything less that 99% effective, but she was adamant "when you look at the Meta-analysis, it's only 70% effective, I took a class!!"

So, slightly freaked out and being a researcher myself with access to one of the best library collections in Canada, I pub-medded the shit out of that. I looked at ever.single.article I could find on the IUD (copper) and I found zero articles that claimed that it was only 70% effective. What I did find was that rates of expulsion are more likely if you are nulliparious (i.e. never had kids) or if you are under 20. And if the IUD is even partially expulsed, it becomes essentially ineffective. So the only way that I can fathom that she got the 70% is by taking into account the people where it was expulsed and thus became pregnant? To me, that's interpretting it wrong (but yo, that happens all the time). As a result, I check my IUD everyday for the strings and possible expulsion, and plan on checking it regularly.

But has anyone else heard about this "not actually 99%" effectiveness business? She, frankly, sounded alarmist to me and the IUD is SUCH a good option if you want non-hormonal birth control. I think it's a shame if sexologist students are being taught these poor numbers without the proper statistical understanding.

ETA: typos etc.