Maturitas 51 (2005) 207–214 Continuous combined parenteral estrogen substitution and intrauterine progestogen delivery: the ideal HST combination? Dirk Wildemeersch a,* , Dirk Janssens b , Steven Weyers c a Contrel Research, Technology Park Zwijnaarde, Ghent, Belgium b Gynecologische Dienst, Turnhout, Belgium c Department of Obstetrics and Gynecology, University Hospital, Ghent, Belgium Received 28 May 2004; received in revised form 13 August 2004; accepted 19 August 2004 Abstract Objective: To evaluate ease of insertion, acceptability and endometrial safety of a novel, miniature intrauterine, T-shaped, levonorgestrel (LNG)-releasing intrauterine system (IUS), Femilis TM Slim LNG-IUS (Contrel Research, Belgium), combined with parenteral estrogen substitution therapy (EST) in postmenopausal women. Design: A prospective, non-comparative, study in postmenopausal women. A 3.0 cm long and 2.0 mm wide coaxial fibrous delivery system, delivering approximately 20 g/day of levonorgestrel (LNG) was used. The drug compartment is provided with crossarms fixed to the upper part of the drug delivery rod. The calculated duration of release of the system is at least 5 years. The majority of women received percutaneous 17 estradiol (Oestrogel ® , Besins Int., Belgium), 1.5 mg daily on a continuous basis, which provides sufficient blood levels of estrogen in most women to suppress climacteric symptoms and protection against bone loss. Primary outcome measures: ease of insertion, retention and side effects of the T-LNG Slim IUS. Secondary outcome measures: endometrial safety assessed by transvaginal ultrasound examination and by endometrial biopsy in a subset of women. Results: One hundred and seventy insertions were performed in postmenopausal women with median age of age 56.6 (range 43.5–80.3). Insertion was easy in 161 (94.2%) and difficult in 9 (5.3%) women. Pain at insertion was rated as none in 57 women (33.5%), mild in 105 (61.7%), moderate in 7 (4.1%) and severe in 1 (0.5%) woman. The system was well retained in the uterus as no expulsions occurred. At the time of study analysis, the total number of women-months was 1797.5. Ninety-five women had the T-LNG-IUS in place for periods in excess of 1 year. The study was well followed-up with lost-to-follow-up rate (defined as no follow-up during 12 months) of zero at the time of study analysis. The number of women continuing the method was 160 (94.1%) including four women which were released from follow-up for various non-medical related reasons. The histological examinations conducted in 105 women showed predominantly inactive endometrium characterized by a pseudo-decidual reaction of the endometrial stroma with endometrial atrophy. The mean thickness (double-layer) of the endometrium was 3.3 mm (range 2–5 mm) which correlated well with the histology results. * Corresponding author. Present address: Piers de Raveschootlaan 125, 8300 Knokke, West-Vlaanderen, Belgium. Tel.: +32 50 600 900; fax: +32 50 622 429. E-mail address: dirk.wildemeersch@contrel.be (D. Wildemeersch) 0378-5122/$ – see front matter © 2004 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.maturitas.2004.08.008