Mirena + birth control pills?

[kinomaniac87.livejournal.com]

I've had a Mirena for almost two years now. I recently developed a few health issues for which my doctor put me on birth control pills (Microgestin Fe 1.5/30). She did this without removing the IUD, for reasons I won't go into here 'cause then I'd be writing y'all a novel.

Anyway, I forgot to ask her what this means for my chances of pregnancy prevention. Will these two things work together or no? I'm freaking out a little because I know that one of the main ways Mirena works is by thinning uterine lining to prevent implantation, and the birth control pills stop that from happening. I know that as long as I follow the directions I shouldn't ovulate while on the pills, but supposing that did happen, then what?

Comments

[nickelshoe.livejournal.com]

I know that combined pill do also thicken the cervical mucus, but I kind of assumed they did it less effectively. POPs only take 2 days to become effective at preventing pregnancy by thickening the cervical mucus, yet combined pills, which contain more progestin, are not considered effective that quickly. So it looks like estrogen interferes? Not negate, certainly.

However, I have nothing to back that up with. I can't find any studies that attempt to address whether these methods could interfere. Since, as you say, combined pills do thicken cervical mucus, it does seem unlikely that the efficacy would actually be reduced.

In short, you're probably right. Just wish we could say that with some empirical data. I don't want to be alarmist, but I also don't want to give false reassurance.

[knittinggoddess.livejournal.com]

Ah ok. I wondered why you stressed lessened mucous.

FWIW, when I asked a doc about getting on HBC to control acne, she refused on the grounds that I would be increasing hormones in my system beyond what she was comfortable prescribing. She didn't say it would make my Mirena less effective, she didn't say it would give me crummy side effects, she just didn't want to do it. Not sure why, but it could be just "doctor knows best".

[nickelshoe.livejournal.com]

Well, unless studies are actually done, doctors can only guess, too. Meh. If you run across such a study, I hope you post it in VP.