释放左旋18-甲基炔诺酮(20μg)宫内节育器的研究回顾

Review on studies of levonorgestrel-releasing IUD(20 μg)[STBZ]

目的总结我所对释放20μg左旋18甲基炔诺酮宫内节育器(LNGIUD)的研究,以阐明其作用机理、长效避孕效用和安全性。方法本文是我所发表的22篇临床报告和研究论文的综合分析。结果观察100例避孕效果,使用8年仅1例妊娠,续用率为52%,因医学原因取器为32.2%。观察10例随访1年有排卵周期者占44.8%,置器6年后,14例中有排卵周期者占78.5%;血清LNG水平有排卵者低,无排卵者高,提示闭经是高浓度LNG对子宫内膜的局部作用。形态学观察显示置器后子宫内膜增生受到抑制,内膜细胞核DNA含量明显下降,内膜细胞雌激素受体(ER)、孕激素受体(PR)表达受到抑制,内膜血管细胞因子VIII(FVIII)活性明显减低。提示月经的改变是LNGIUD对子宫内膜的局部作用。观察34例特发性月经过多的治疗达3年,月经血量(MBL)显著下降,血红蛋白(Hb)和铁蛋白明显增加。结论释放20μg的LNGIUD是一个安全、高效、长效、可逆的避孕方法。主要优点是降低MBL,可接受性高,适合于我国实际应用。尤其对月经过多和贫血的妇女,更应优先选择。

Objective: To review the studies of levonorgestrel-releasing intrauterine devices (LNG-IUD 20 μg/day, Leiras) in our institute to understand its mechanism and long-term contraceptive efficacy and safety.Method: The data from 22 of our related published papers were summerized. Result: After insertion of LNG-IUD for 8 years, only 1 pregnancy occurred in 100 women. The continuation rate was 52% and the medical removal rate was 32.2%. Ten women were followed-up for 1 year and 44.8% showed ovarian cycle. 78.5% of 14 women with the IUD for 6 years had the luteal function. Serum LNG low levels were shown in the women with ovarian function. It indicated that high LNG levels in the endometrium induced amenorrhea. Morphometric study of the endometrium revealed the suppression of endometrial proliferative activity. A significant decrease of endometrial DNA content, the inhibition of ER and PR expression in endometrial cells were also observed. The synthesis and release of endometrial endothelial factor VIII might be inhibited after insertion. These studies also indicated the mechanism of action is mostly on the endometrium. Thirty-four patients with idiopathic menorrhagia were treated by LNG-IUD insertion for 3 years. After insertion of LNG-IUD, menstrual blood loss became markedly reduced, hemoglobin and serum ferritin levels were significant increased. Conclusion: LNG-IUD (20 μg) is a highly effective, long term safe and reversible contraceptive method. The main advantage is the decrease of MBL. It is highly accepted by our women, particularly for those with menorrhagia and anemia.