Long-term contraception with the levonorgestrel 20 mcg/day (LNg 20) and the copper T 380Ag intrauterine devices: a five-year randomized study

Abstract

An intrauterine device, releasing approximately 20 micrograms/day of levonorgestrel (LNg 20), used by 1124 women, was studied in a randomized trial of five years duration in comparison with the Copper T, model TCu 380Agm in 1121 women. At five years, the gross cumulative pregnancy rate of 1.1 +/- 0.5 per 100 among users of the LNg 20 devices was not significantly different from the rate of 1.4 +/- 0.4 per 100 experienced by users of the Copper T 380Ag. The steroid-releasing IUD had significantly higher termination rates for expulsion and amenorrhea, a significantly lower termination rate for other menstrual problems and pain, and a lower continuation rate. The five-year continuation rate among women using the TCu 380Ag was 40.6 per 100 as compared with that of 33.0 per 100 among women randomized to the LNg 20 device (P less than .001). Terminations attributed to amenorrhea with the LNg device primarily account for differences in continuation. These two intrauterine devices are the most effective long-term, reversible IUDs yet reported in the literature. No other contraceptive methods have exhibited such low long-term pregnancy rates in randomized comparative trials.

PIP: An IUD. releasing approximately 20 mcg/day of levonorgestrel (LNg 20) was studied in a randomized trial of 5 years duration. 1124 women comprised this group and were compared to another group of 1121 women who used the TCu 380 Ag. At the end of 5 years, the gross cumulative pregnancy rate was 1.1 +or- 0.5/100 among LNg 20 devise users; this was not significantly different from the rate of 1.4 +or- 0.4/100 experienced by those using the TCu 380 Ag. The steroid-releasing IUD had significantly higher rates for expulsion and amenorrhea, a significantly lower termination rate for other menstrual problems and pain, and a lower continuation rate. The 5-year continuation rate among women using the TCu 380 Ag was 40.6/100 as compared to 33.0/100 among women randomized to the LNg 20 device (p0.001). Terminations attributed to amenorrhea with the LNg device are largely responsible for the differences in continuation.