Bleeding pattern and endometrial changes during continuous combined hormone replacement therapy. The Ogen/Provera Study Group

Obstet Gynecol. 1998 May;91(5 Pt 1):678-84. doi: 10.1016/s0029-7844(98)00038-6.


Objective: To establish the optimum oral daily dose of micronized medroxyprogesterone acetate, given in combination with a fixed oral dose of estrone (E1) sulfate as hormone replacement therapy, that provides endometrial protection and induces cessation of vaginal bleeding.

Methods: This multicenter, randomized, double-blind study was conducted for 2 years. Five hundred sixty-eight postmenopausal women were randomized to take E1 sulfate 1.25 mg daily and one of three doses of medroxyprogesterone acetate (2.5, 5, or 10 mg) daily. Any vaginal bleeding was recorded by patients in a daily diary, and endometrial biopsies were performed at entry into the study and at 3, 12, and 24 months.

Results: Forty-two percent of all women reported some bleeding at month 3 of therapy. However, by month 6, 76.5, 80.1, and 80.9% of women were amenorrheic in the 2.5-, 5-, and 10-mg medroxyprogesterone acetate groups, respectively. Over time, the percentage of women with no bleeding increased in each group, and by 24 months 91.5, 89.9, and 94.3% were amenorrheic in the 2.5- and 10-mg medroxyprogesterone acetate groups, respectively. Approximately 10% of women continue to have some bleeding, regardless of the dose of medroxyprogesterone acetate. There were no statistically significant differences in the number of women with bleeding at any time point between the three groups. There were no cases of endometrial hyperplasia reported in the study population over the 2 years.

Conclusion: All three studied doses of medroxyprogesterone acetate, given in combination with 1.25 mg of E1 sulfate, provide adequate endometrial protection and render approximately 80% of women amenorrheic by 6 months of therapy.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Biopsy, Needle
  • Double-Blind Method
  • Endometrium / drug effects*
  • Endometrium / pathology
  • Estrogen Replacement Therapy* / adverse effects
  • Estrogens, Conjugated (USP) / administration & dosage
  • Estrogens, Conjugated (USP) / adverse effects
  • Estrone / administration & dosage
  • Estrone / adverse effects
  • Estrone / analogs & derivatives
  • Female
  • Humans
  • Medroxyprogesterone Acetate / administration & dosage
  • Medroxyprogesterone Acetate / adverse effects
  • Middle Aged
  • Postmenopause / physiology
  • Progesterone Congeners / administration & dosage
  • Progesterone Congeners / adverse effects
  • Uterine Hemorrhage / chemically induced*


  • Estrogens, Conjugated (USP)
  • Progesterone Congeners
  • Estrone
  • Medroxyprogesterone Acetate
  • estrone sulfate