Three-year efficacy and acceptability of the GyneFix® 200 intrauterine system

Abstract

Objective This study was conducted to evaluate the efficacy of a “mini” version of the frameless intrauterine system (IUS; GyneFix®), which has a copper surface area of approximately 200 mm 2. The small GyneFix version consists of four copper cylinders instead of six and is only 2 cm long. Materials and methods A total of 392 insertions were performed in an open nonrandomized study in parous (76%) and nulligravid/nulliparous (24%) women in Belgium and China. This interim analysis reports on 13,699 women-months of use. All women were followed-up for a minimum of 12 months, up to 3 years and longer. Results Four pregnancies occurred with the GyneFix 200 IUS in this study, of which one occurred after unnoticed expulsion of the device, yielding a cumulative failure rate of 0.48 at 3 years. The cumulative removal rate for medical reasons was 1.65 at 3 years and the expulsion rate was 0.39. These low event rates resulted in a high continuation of use (93.92 at 3 years). Neither perforations nor pelvic inflammatory disease cases were encountered in this study. Conclusion The present study suggests that the GyneFix 200 IUS is highly effective and probably as effective as the standard GyneFix IUS. This is attributed to the anchoring of the device to the fundus of the uterus, promoting its contraceptive action. The total surface area of the device, releasing a maximum amount of copper ions, is the fundamental difference between it and conventional IUDs and is probably essential in obtaining the high contraceptive efficacy seen in this study. The small total surface area of the GyneFix 200 IUS also minimizes menstrual bleeding and is an improvement over larger types of conventional IUDs, as indicated by the low removal rate for abnormal bleeding with the small GyneFix.