PROFAMILIA, P.O. Box 1053, Santo Domingo 10401, Dominican Republic.
Contraception. 2010 Nov;82(5):418-27. doi: 10.1016/j.contraception.2010.04.012. Epub 2010 May 20.
Development efforts on contraceptive vaginal rings were initiated over 40 years ago based on two principles: the capacity of the vaginal epithelium to absorb steroids and the capacity of elastomers to release these hormones at a nearly constant rate. Numerous models of contraceptive vaginal rings (CVRs) have been studied, but only two have reached the market: NuvaRing, a combined ring that releases etonogestrel (ENG) and ethinylestradiol (EE), and Progering, a progesterone-releasing ring for use in lactating women. The main advantages of CVRs are their effectiveness (similar to or slightly better than the pill), ease of use without the need of remembering a daily routine, user's ability to control initiation and discontinuation, nearly constant release rate allowing for lower doses, greater bioavailability and good cycle control with the combined ring. The main disadvantages are related to the mode of delivery; CVRs may cause vaginal discharge and complaints, ring expulsion is not uncommon, the ring may be felt during coitus and vaginal insertion may be unpleasant for some women. The studies reviewed in this article provide evidence that CVRs are safe, effective and highly acceptable to women. There is no doubt that CVRs offer a new, effective contraceptive option to women, expanding their available choices of hormonal contraception.
避孕阴道环的研发工作始于 40 多年前，其基于两个原理：阴道上皮吸收甾体激素的能力和弹性体以近乎恒定的速率释放这些激素的能力。已经研究了许多避孕阴道环（CVR）模型，但只有两种进入市场：NuvaRing，一种释放依托孕烯（ENG）和乙炔雌二醇（EE）的组合环，以及 Progering，一种用于哺乳期妇女的孕激素释放环。CVR 的主要优点是其有效性（与药丸相似或略好）、无需记住日常使用的便利性、使用者能够控制开始和停止使用的能力、允许使用较低剂量的近乎恒定释放率、更高的生物利用度和联合环的良好周期控制。主要缺点与输送方式有关；CVR 可能会导致阴道分泌物和不适，环脱落并不少见，在性行为期间可能会感觉到环，并且阴道插入对某些女性来说可能不愉快。本文综述的研究提供了证据表明 CVR 是安全、有效和高度被女性接受的。毫无疑问，CVR 为女性提供了一种新的、有效的避孕选择，扩大了她们可选择的激素避孕方法。
