Intrauterine levonorgestrel delivered by a frameless system, combined with systemic estrogen: acceptability and endometrial safety after 3 years of use in peri- and postmenopausal women

Abstract

Objective: To evaluate the acceptability and endometrial safety of a novel intrauterine drug delivery system, FibroPlant-levonorgestrel (LNG), combined with estrogen therapy (ET) in 150 peri- and postmenopausal women, followed-up for at least 3 years.

Design: This was a prospective, non-comparative study in peri- and postmenopausal women. In the majority of women, treatment with the FibroPlant-LNG intrauterine system (IUS), combined with ET, was initiated during the perimenopausal transitional phase to establish a smooth transition to menopause and suppress the endometrium to prevent endometrial proliferation and bleeding. A 3.5-cm long coaxial fibrous delivery system, delivering approximately 14 microg LNG/day, was used. The calculated duration of release of the system is at least 3 years. The majority of women received percutaneous 17beta-estradiol (Oestrogel), 1.5 mg daily on a continuous basis, which provides sufficient blood levels of estrogen in most women to suppress climacteric symptoms and protect against bone loss.

Outcome measures: To measure acceptability, women were asked, after they had the IUS in place for a minimum of 3 years, if they would like to continue the combined regimen and if they would accept renewal of the IUS. Endometrial safety was evaluated by transvaginal ultrasound examination and endometrial biopsy in a subset of 101 women prior to replacement of the IUS.

Results: Ninety-four insertions were done in perimenopausal and 56 in postmenopausal women aged between 33 and 78 years. Of the total group of 150 women, 132 women (88.0%) accepted replacement of the IUS and ten are waiting for replacement. This group includes nine women who will receive a second replacement. The number of women continuing the method is 142 (94.6%). Histological examinations conducted on endometrial biopsies from 101 postmenopausal women prior to replacement, after an average period of use of the regimen of 40 months (range 25-50 months), showed predominantly inactive endometrium characterized by pseudodecidual reaction of the endometrial stroma with endometrial atrophia, which is in keeping with the effects seen with a progestogenic compound. There were no specimens showing signs of proliferation.

Conclusions: Results suggest that the frameless FibroPlant-LNG IUS is safe, well tolerated, well accepted and effective in suppressing the endometrium during ET. Intrauterine progestogen administration in postmenopausal women can be regarded as fundamentally advantageous compared with systemically applied progestogens, which may have potentially inherent ill side-effects, especially on the breast and cardiovascular system, as reported in the recent literature.