Toivonen J, Luukkainen T, Allonen H
Department of Medical Chemistry, University of Helsinki, Finland.
Obstet Gynecol. 1991 Feb;77(2):261-4. doi: 10.1097/00006250-199102000-00019.
A randomized, multicenter comparison of two intrauterine contraceptive devices (IUDs) was carried out. Nine hundred thirty-seven women were fitted with a copper-releasing IUD, the Nova-T, and 1821 women with an IUD that releases 20 micrograms of levonorgestrel daily. After 36 months, the cumulative gross rates of amenorrhea and hormonal side effects were significantly higher in the levonorgestrel-IUD users. The cumulative 36-month gross pregnancy rate was 3.7 for the Nova-T and 0.3 for the levonorgestrel IUD (P less than .001), demonstrating the levonorgestrel IUD's high contraceptive efficacy. For the first time, a protective effect of the levonorgestrel IUD against pelvic inflammatory disease as compared with the Nova-T was seen statistically. The cumulative 36-month gross rate of pelvic inflammatory disease was 2.0 in Nova-T- and 0.5 in levonorgestrel-IUD users (P less than .013). This significantly lowered incidence of pelvic inflammatory disease may help to solve one of the major concerns associated with intrauterine contraception.
开展了一项对两种宫内节育器（IUD）的随机多中心比较研究。937名女性安装了含铜宫内节育器Nova-T，1821名女性安装了每日释放20微克左炔诺孕酮的宫内节育器。36个月后，左炔诺孕酮宫内节育器使用者的闭经和激素副作用累积总发生率显著更高。Nova-T的36个月累积总妊娠率为3.7%，左炔诺孕酮宫内节育器为0.3%（P＜0.001），表明左炔诺孕酮宫内节育器具有高避孕效果。首次在统计学上观察到与Nova-T相比，左炔诺孕酮宫内节育器对盆腔炎有保护作用。Nova-T使用者的盆腔炎36个月累积总发生率为2.0%，左炔诺孕酮宫内节育器使用者为0.5%（P＜0.013）。盆腔炎发病率的显著降低可能有助于解决与宫内避孕相关的一个主要问题。
