Vaginal micronized progesterone in continuous hormone replacement therapy. A prospective randomized study.

Area of Science:

• Endocrinology
• Gynecology
• Pharmacology

Background:

• Hormone replacement therapy (HRT) in post-menopausal women requires progestogen co-administration to prevent endometrial proliferation.
• Different progestins exhibit varying metabolic and tissue effects based on dosage and administration route.
• Evaluating progestin impact on lipid profiles and endometrial morphology is crucial for HRT management.

Purpose of the Study:

• To compare the effects of three different progestin regimens on lipid profiles and endometrial morphology in post-menopausal women undergoing HRT.
• To determine the optimal progestin for endometrial transformation in women on continuous estrogen therapy.

Main Methods:

• Prospective randomized study of 60 post-menopausal women on continuous transdermal ethinyl-estradiol.
• Progestin regimens included: medroxyprogesterone acetate (MPA) orally, transdermal nor-ethisterone acetate (NETA), and micronized progesterone (MP) vaginally.
• Endometrial morphology and lipid profiles were assessed over one year.

Main Results:

• No significant alterations in lipid profiles were observed across all tested progestin regimens.
• Oral MPA and transdermal NETA more frequently led to endometrial atrophy.
• Vaginal micronized progesterone (MP) significantly induced a functional-like secretory endometrium (p<0.005 at 6 months, p<0.001 at 1 year).

Conclusions:

• Vaginal micronized progesterone (MP) is an effective alternative for endometrial transformation in post-menopausal women on continuous HRT.
• Cyclic vaginal MP administration supports a functional-like secretory endometrium, unlike other tested progestins.
• MP offers an acceptable option for women desiring to maintain a cyclical pattern during HRT.