Frameless versus classical intrauterine device for contraception.
BACKGROUND
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. The introducer for the frameless device was modified following reports of early expulsions of the device.


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


METHODS
We searched the Cochrane Controlled Trial Register (Cochrane Library Issue 1, 2001), MEDLINE, EMBASE and Popline to Dec 2000, and reference list of articles.


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


METHODS
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 general variance-based method to combine trials, and tested the results for heterogeneity.


RESULTS
Three trials were included in the review involving over 5,800 women randomised to either a frameless device or TCu380A, with data up to eight years for the largest, and with a total experience of 23,000 women-years. All three trials excluded nulliparous women. 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; by the third year the expulsion rate with the frameless device was lower (relative risk 0.41, 95% confidence intervals 0.19 to 0.87) with no difference in pregnancy rate. 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).


CONCLUSIONS
There are insufficient data to show that problems of early expulsions have been overcome with the new introducer used in GyneFix. Apart from that, the frameless device performs similarly to TCu380A, and appears to have a lower pregnancy rate in later years, although the absolute difference is small.
O'Brien
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PA
Services for Women, Parkside Health, St Charles Hospital, Exmoor St, London, UK, W10 6DZ. PaulOBrien@care.prestel.co.uk
Marfleet
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D003267:Contraception; D004867:Equipment Design; D005260:Female; D006801:Humans; D007434:Intrauterine Devices; D016032:Randomized Controlled Trials as Topic