Hormonal Changes: Two major hormones in a woman’s body, estrogen and progesterone, influence the growth of fibroids. These hormones help thicken the uterine wall during the menstrual cycle. When these hormones are produced in excess, tumors are likely to grow. When the levels of these hormones increase during pregnancy, the tumors are likely to enlarge, and when the hormone levels decrease after menopause, they are likely to shrink.
Genetics: If your mother or sister has had uterine tumors in your family, you are more likely to get them too.
Growth Factors: Excessive production of certain substances (Insulin-like growth factor) in the body can cause the growth of fibroids.
Epigenetic Changes: Certain genetic changes that cause normal cells to turn into tumors can occur in the structure of cells.
