University of Arizona, Tucson, AZ, USA.
Am Fam Physician. 2014 Mar 15;89(6):445-50.
Three intrauterine devices (IUDs) are available in the United States: the copper T 380A and two levonorgestrel-releasing IUDs, one that releases 20 mcg of levonorgestrel per 24 hours, and one that releases 14 mcg per 24 hours. All are safe and effective methods of contraception that work predominantly by prefertilization mechanisms. The copper T 380A IUD may be placed in nonpregnant women at any time in the menstrual cycle. The prescribing information for the 20- and 14-mcg levonorgestrel-releasing IUDs advises that insertion occur during the first seven days of menses. Insertion immediately after vaginal or cesarean delivery may be considered with the copper T 380A and the 20-mcg levonorgestrel-releasing IUDs; however, expulsion rates are higher than with delayed postpartum insertion. The prescribing information for both levonorgestrel-releasing IUDs advises a waiting period of six weeks postpartum or following second-trimester pregnancy loss. Current guidelines indicate that IUDs are acceptable for use in nulliparous women, in adolescents, and in women who are breastfeeding. They may also be used in women who have a history of sexually transmitted infection, although screening is recommended. IUDs should not be inserted for at least three months after resolution of a sexually transmitted infection. Neither antibiotic prophylaxis nor misoprostol use before IUD insertion is beneficial. If pregnancy occurs, the IUD should be removed if feasible. Possible side effects of levonorgestrel-releasing IUDs include headaches, nausea, hair loss, breast tenderness, depression, decreased libido, ovarian cysts, oligomenorrhea, and amenorrhea. The main side effect of the copper T 380A IUD is increased menstrual bleeding, which may continue even with long-term use.
美国有三种宫内节育器（IUD）：铜 T 380A 和两种左炔诺孕酮释放 IUD，一种每 24 小时释放 20 微克左炔诺孕酮，另一种每 24 小时释放 14 微克。所有这些都是安全有效的避孕方法，主要通过受精前机制发挥作用。铜 T 380A IUD 可在月经周期的任何时间放置于未怀孕的女性体内。20 微克和 14 微克左炔诺孕酮释放 IUD 的说明书建议在月经来潮的头七天内放置。在阴道分娩或剖宫产分娩后立即放置也可考虑使用铜 T 380A 和 20 微克左炔诺孕酮释放 IUD；然而，与产后延迟放置相比，其脱落率更高。两种左炔诺孕酮释放 IUD 的说明书均建议在产后六周或中期妊娠流产后六周等待期后再放置。当前的指南表明，IUD 可用于未生育的女性、青少年和哺乳期女性。对于有性传播感染史的女性，也可以使用 IUD，但建议进行筛查。在性传播感染治愈后，至少应等待三个月再放置 IUD。在放置 IUD 之前使用抗生素预防或米索前列醇均无益处。如果发生妊娠，应尽可能取出 IUD。左炔诺孕酮释放 IUD 的可能副作用包括头痛、恶心、脱发、乳房触痛、抑郁、性欲降低、卵巢囊肿、月经稀少和闭经。铜 T 380A IUD 的主要副作用是经量增加，即使长期使用也可能持续。
