The Copper-Fix (Cu-Fix): a new concept in IUD technology

Abstract

The Copper-Fix (Cu-Fix) is a thread-type copper-bearing device designed to overcome the most common IUD-related problems: bleeding and pain. Two distinctive features--virtual absence of a frame and provision of an anchoring system--make this new intrauterine device the first radical departure from current IUD technology. The Cu-Fix 390 was inserted at intervals in 382 women, and 4851 woman-months of experience had been accumulated at 18 months. The device was exceedingly well retained by the uterus (expulsion rate 0.6 at 18 months) and the removal rate for bleeding/pain was low (3.1 at 18 months). Serious complications did not occur; the pregnancy rate amounted to 0.3 at 18 months, with a continuation rate of 87.6%, which includes an 8.1% removal rate for pregnancy wish. Cardinal event rates were not influenced by the age or gravidity status of the recipient.

An evaluation of six new intrauterine devices

“…At the end of 12 months of use, the pregnancy rate was 0.3 (based on a single pregnancy, probably due to an unnoticed expulsion), the expulsion rate was 0.6, and the removal rate for bleeding and/or pain was 3.1. The one-year continuation rate was 94.2 [6]. Batar conducted a noncomparative study of 344 women using the Flexigard-330, and showed similarly favorable results [17].…”

“…The following analyses compare the performances of the CU-SAFE [5], Cu-Fix [6,17], Ombrelle [7,19], and Fincoid IUDs [20] (S Kaivola, personal communication) with the TCu380A, an IUD whose reputation for excellent performance is well-established. The study by Sivin and Tatum reported in 1981 was used as an historical comparison [21] (Table 1).…”

“…This 'frameless' IUD is a revolutionary deviation from the concept of a 'plastic IUD frame which bears a medicated component' [6]. The prototype consists of six sleeves of copper (99.99% pure), each with a length of 5 mm and a diameter of approximately 2.2 mm.…”

“…This modification is called Flexigard 330, as the copper surface area is reduced to 330 mm 2. The proximal end of the suture consists of a single knot which, using a specially designed inserter, is driven into the fundal myometrium to a depth of 1 cm in order to permanently fix the device into the uterine muscle [6]. The special anchoring system of the Cu-Fix IUD and Flexigard IUD should prevent expulsion if insertion is done properly.…”

Intrauterine contraceptives that do not fit well contribute to early discontinuation

“…Significant reasons for discontinuation were expulsion, bleeding and/or pain. 20 The initial trials with the frameless IUD conducted in Belgium, and later internationally, in parous and nulliparous women, were promising 21,22 . However, the WHO randomised clinical trial comparing the TCu380A with the frameless Flexigard 1 IUD (Flexigard 1 , developed by GynoPharma, Inc. in the USA, uses the same frameless design as that of the current GyneFix 1 IUD but a different inserter), involving parous women only, did not show a difference in removal rate for bleeding and pain 23 .…”