Original research article Efficacy of a mini version of the frameless GyneFix intrauterine system (IUS) with effective copper surface area of 200 mm 2

This study was conducted to evaluate the efficacy of a ‘mini’ version of the frameless intrauterine system (IUS) (GyneFix) that has a copper surface area of approximately 200 mm 2 . The GyneFix-mini consists of four copper cylinders instead of six and is only 2 cm long. A total of 301 insertions were performed in an open nonrandomized pilot study in parous (77%) and nulligravid/nulliparous (23%) women in Belgium and China. This interim analysis reports on 4110 women-months of use. All women were followed-up for a minimum of 12 months. Two pregnancies occurred with the mini GyneFix IUS in this study. However, only one occurred with the device in situ. The cumulative removal rate for medical reasons (bleeding and pain) was 0.39 at 1 year. The expulsion rate was 1.04. These low event rates resulted in a high continuation rate (95.02 at 1 year). Neither perforations nor pelvic inflammatory disease cases were encountered in this study. This study indicates that only a minimal amount of copper, positioned in the upper part of the uterine cavity, is sufficient to provide a high contraceptive effect. This is made possible by anchoring the active contraceptive substance to the fundus of the uterus. The fact that 100% of the copper surface area of the frameless IUS is available for copper release is an additional advantage. © 2002 Elsevier Science Inc. All rights reserved.