Factors associated with withdrawal bleeding after administration of oral dydrogesterone or medroxyprogesterone acetate in women with secondary amenorrhea.

The effectiveness of two treatment regiments in inducing withdrawal bleeding in secondary amenorrhea was compared and correlated with the endometrial thickness and endogenous E2 and progesterone concentrations. A prospective, randomized and double-blind study was designed at the Outpatient Clinic of Reproductive Endocrinology, Central Emek Hospital, Afula, Israel. Seventy-seven premenopausal women with oligomenorrhea or amenorrhea, 48 of whom qualified for the study, underwent a 5-day course of either medroxyprogesterone acetate (MPA) 5 mg b.i.d. or dydrogesterone (DG) 10 mg b.i.d. Endogenous pretreatment values of E2 and progesterone and endometrial thickness (by transvaginal ultrasonography) were correlated with the bleeding response. Withdrawal bleeding occurred in 93% of women taking either MPA or DG. Side effects occurred similarly among the groups. Lipid concentrations were unchanged. Endogenous E2 and progesterone were limited predictive value for withdrawal bleeding. Endometrial thickness as measured by transvaginal sonography correlated significantly with the bleeding response.