Detailed definition
The myometrium is a thick layer of interlacing smooth muscle that constitutes the bulk of the uterine wall. It contracts during labor (driven by oxytocin) and produces menstrual cramping (driven by prostaglandins). Estrogen is a major growth signal for myometrial cells, which is why fibroids — benign smooth muscle tumors of the myometrium — are estrogen-responsive, often shrinking after menopause. After menopause, in the absence of estrogen stimulation, myometrium and any pre-existing fibroids generally shrink.
Why it matters in menopause
For postmenopausal women with prior fibroids, starting systemic HRT may produce some return of fibroid-related symptoms (pelvic pressure, occasional bleeding) although clinically significant regrowth is uncommon at typical menopause-replacement doses. For perimenopausal women with active fibroids and heavy bleeding, the LNG-IUD is often a useful tool that addresses both bleeding and provides endometrial protection.
Related terms
Sources
External references: Wikipedia.