Uterine fibroids are hormone sensitive, and they literally are powerhouses of estrogen. . All uterine muscle cells have receptors for estrogen and progesterone. Thus a uterine cell s stimulated to grow by these hormones. A uterine fibroid tumor has a greater density of these receptors than in the case of most uterine cells. In pregnancy this is a very effective strategy, hormones trigger growth as a pregnancy progresses. But in the case of uterine fibroid, the excessive growth is the source of many of the complications of fibroids.
The hormone sensitivity of uterine fibroids also produces a estrogen excessive environment. This is a situation where the uterine fibroids adhere (also known as binding) to the estrogen molecules. Thus there is more estrogen and this can be responsible for many of the associated symptoms. Not only that but the fibroid cells are able to manufacture estrogen from other molecules. This also responsible for the powerhouse of estrogen. Obese women, or women with other high estrogen conditions like PCOS are more likely to have uterine fibroids.
Oddly women who smoke have lower risk of fibroids do to the fact that their estrogen levels are lower.
If your fibroid has grown or changed, it is important to get accurate ultrasound measurements measurements, to determine if this is true. It is equally important to know if you have other reasons for excess estrogen so that you can try to mitigate the side effects.. Generally the largest fibroid present in a uterus grows about 35% per year! It has never been shown that birth control pills or even other estrogen hormone treatments cause fibroids to grow. It is not clear why this would be so. It could be the types of hormones, the dosage, or the fact that local and genetic factors are so dominant that supplemental hormones don't have an effect. Since a uterine fibroid is a powerhouse of estrogen it is probably possible to alter that fact and help to shrink the fibroid. That is where all the new research is going. Antiprogesterone and other new hormonal therapies do however help to shrink fibroids. If you are interested in participating in a clinical research study of uterine fibroids call Women's Health Practice, 217-356-3736.