Frameless versus classical intrauterine device for contraception

  • Review
  • Intervention




The frameless intrauterine device (IUD) dispenses with the frame in the classical IUD and holds the device in the uterus by anchoring one end of a nylon thread in the fundal myometrium, to which copper sleeves are attached.


This review examines the hypothesis that the frameless IUD Gynefix reduces risk of expulsion and pregnancy, and the problems of bleeding and pain necessitating early removal.

Search methods

We searched the Cochrane Controlled Trial Register (Cochrane Library Issue 2, 2004), MEDLINE, and Popline from 1980 to March 2004, and reference list of articles.

Selection criteria

We selected for the review randomised trials that compared the frameless device to a classical framed device for contraception.

Data collection and analysis

Both authors extracted data independently. We contacted study author for additional data. We calculated rate ratios and rate differences for cumulative rates for each outcome at yearly intervals. We used the inverse variance-based method to combine trials, and tested the results for heterogeneity.

Main results

Four trials were included in the review involving 5,939 women randomised to either a frameless device or TCu380, with data up to eight years for the largest, and with a total experience of 23,180 years. Apart from one small trial, nulliparous women were excluded from the trials. The two earlier trials used a prototype introducer and there was a higher expulsion rate at one year (relative risk 2.48, 95% confidence intervals 1.89 to 3.26). However, between two and six years in the large WHO trial the risk of pregnancy was lower with the frameless device (relative risk 0.53, 95% confidence intervals 0.32 to 0.91). In a recent trial using GyneFix with a new introducer early expulsions and pregnancies were not statistically different from the control device. Removals rates for excessive bleeding and/or pain were no different between the devices (relative risks 0.92, 95% confidence intervals 0.74 to 1.14, at one year and 1.13, 0.93 to 1.37, at six years). There was a tendency towards fewer removals for pain in early years but no difference at six years (relative risk 1.13, 95% confidence intervals 0.93 to 1.37).

Authors' conclusions

There is insufficient data to show that problems of early expulsions have been overcome with the modified introducer used in GyneFix. Apart from that, the frameless device performs similarly to TCu380, and appears to have a lower pregnancy rate in later years, although the absolute difference is small.








我們搜尋了考科藍資料庫內的相關研究(Cochrane Library Issue 2, 2004), MEDLINE, 以及Popline 1980至2004年三月間的文獻,以及相關參考書目




兩位作者是獨立蒐集數據的.我們也與研究報告的作者接洽,以獲得更多資料.我們以年為單位,計算各概率的比率及差異性,以統計各結果的累進率.我們採用inverse variancebased方法來合併各試驗的結果,以及比較各試驗的異質性


此篇回顧囊括了四個隨機試驗,共5939位受試婦女隨機分配使用無支架型子宮內避孕器或TCu380,其中最大的一個試驗橫跨了8年的研究,四個試驗合計共23180年的研究經歷,這些不包括其中一個小型研究中,未曾生育過的受試者.其中兩個較早的研究使用了原型導引器(prototype introducer)而一年內避孕器脫出的機率較高(相對風險(relative risk) 2.48, 95% 信賴區間(confidence intervals): 1.89 – 3.26).在一項WHO的大型研究中,受試者使用2到6年的子宮內避孕器,使用無支架型子宮內避孕器可有較好的避孕效果(相對風險(relative risk) 0.53, 95% 信賴區間(confidence intervals) 0.32 to 0.91).一個最近的研究顯示,使用GyneFix配合新型導引器,早期避孕器脫出及懷孕的機率,與控制組的傳統型避孕器並無差異.因裝置後出血或疼痛而取出避孕器的機率,二者也無不同(相對風險 0.92, 95% 信賴區間:1 年:0.74 – 1.14, 6年:1.13, 0.93 – 1.37).有一個傾向是,避孕器在植入早期數年內因疼痛而移除的機率並不高,但在六年內的移除率並無差別(相對風險 1.13, 95% 信賴區間0.93 – 1.37).





此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。



Plain language summary

The frameless IUD performs similarly to traditional IUDs but does not reduce bleeding and pain associated with standard IUDs.

Devices placed in the uterus are highly effective at preventing pregnancy. Traditional intrauterine devices (IUD) with plastic frames have side effects such as excessive bleeding and pain that were thought to be due to the frame. This review found that symptoms of bleeding and pain, and contraceptive efficacy were not improved with the frameless device. Trials are needed to see if the frameless IUDs could benefit women who have not had children.