Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice.
Usually absence of menstrual periods for around 12 months without any medical or iatrogrnic causes can be considered as menopause
Though your fsh levels are elevated that alone cannot be taken as conformative evidence of Menopause, as sometimes in perimenopausal stage also fsh levels can be elevated and also hormonal
supplements can alter the levels.
So, better to recheck the levels of FSH before the due date of Mirena
, if levels are persistently high and endometrial thickness in ultrasound
is less than or equal to 4mm, there is possibility of of nearing menopause.
In that case you can wait and observe your menstrual cycles for two to three months , if you are not getting menstrual periods, no need of Mirena.
But till that better to use barrier contraception
like condoms to be on safe side.
Hope I have answered your query and I will be happy to answer any further queries.