02-09-2013, 02:31 PM
Join Date: Oct 2009
Location: NE Iowa
Re: Faint line?
directly from Mirena website:
How does Mirena work to prevent pregnancy?
Mirena (levonorgestrel-releasing intrauterine system) releases small amounts of the hormone levonorgestrel directly into your uterus.
There is no single explanation for how Mirena works. Mirena may:
Thicken cervical mucus to prevent sperm from entering your uterus
Inhibit sperm from reaching or fertilizing your egg
Make the lining of your uterus thin
Mirena (levonorgestrel-releasing intrauterine system) may stop the release of your egg from your ovary, but this is not the way it works in most cases. Most likely the above actions work together to prevent pregnancy. Like other forms of birth control, Mirena is not 100% effective.
So basically - they aren't exactly sure how it works....it might create a hostile enviroment for some sperm, it might just make the lining thin (but sperm and egg still might meet)