Hi ocallagd
You've posted the same query in several areas - it's actually all the same forum so for future reference it's only necessary to post once! However I see you didn't get proper replies to the other pleaces you posted so will try to help!
I'm just a bit confused because it is usual as far as I understand to do a hysteroscopy at the same time as biopsy as I thought they would need the camera in order to do the biopsy? Also strange to refer for this straight after the Mirena has been fitted?
Presumably they want to check the whole womb area for fibroids etc? If you are peri-menopausal and taking hRT then the womb will vary in thickness according to the stage of the cycle so a thick lining per se is not serious. What stage of the cycle did you have the scan showing 12.6 mm? If on HRT scans should be done immediately following the bleed when the lining is at its thinnest. Even so if you are peri with your own hormones adding to the mix it might be inaccurate.
The progestogen in the Mirena should gradually thin the lining although I imagine you may get bleeding over the next few months while it settles down?
Are you also having oestrogen patches for menopausal symptoms?
let us know the outcome and hope all is well!
Hurdity x
