Which of the following hormone promotes the development of fibroids ?

Both estrogen and progesterone appear to promote the development of fibroids. Factors that increase overall lifetime exposure to estrogens, such as obesity and early menarche, increase the incidence. Decreased exposure to estrogen found with smoking, exercise, and increased parity is protective.Progesterone is impoant in the pathogenesis of fibroids, which have increased concentrations of progesterone receptors A and B compared with normal myometrium. The highest mitotic counts are found in fibroids at the peak of progesterone production.Ref: Berek and Novak&;s Gynecology; 15th edition; Chapter 15; Uterine Fibroids