Gaspard U, Kridelka F
CHU de Liege, Policlinique Universitaire, Belgique.
Rev Med Liege. 2010 Dec;65(12):700-5.
Emergency contraception is a second chance for prevention of pregnancy after unprotected intercourse. Hormonal emergency contraception with levonorgestrel 1.5 mg, only provides an effective contraception from 0 to 72 hours after intercourse with decreasing effectiveness as time elapses. It was accordingly mandatory to develop an alternative approach with a stable contraceptive efficacy and good tolerance for 5 days, knowing additionally that the estimated lifespan of sperm in the female genital tract is about 5 days. In comparative studies bearing on more than 3000 young women, the progesterone receptor modulator (PRM) ulipristal acetate, a progesterone antagonist (taken in a single dose of 30 mg), or levonorgestrel (1.5 mg) were administered. Results indicated that the PRM was as effective as levonorgestrel, or even more, kept a stable efficacy for 120 hours after an unprotected intercourse, and was well tolerated. This establishes ulipristal acetate as the new standard for hormonal emergency contraception.
紧急避孕是在无保护性交后预防怀孕的第二次机会。含1.5毫克左炔诺孕酮的激素紧急避孕措施，仅在性交后0至72小时内提供有效避孕，且随着时间推移有效性会降低。因此，鉴于已知精子在女性生殖道中的估计存活时间约为5天，开发一种具有稳定避孕效果且5天内耐受性良好的替代方法就成为了必然。在针对3000多名年轻女性的对比研究中，给予了孕激素受体调节剂（PRM）醋酸乌利司他（一种孕激素拮抗剂，单次服用30毫克）或左炔诺孕酮（1.5毫克）。结果表明，PRM与左炔诺孕酮效果相当，甚至更佳，在无保护性交后120小时内保持稳定效果，且耐受性良好。这确立了醋酸乌利司他作为激素紧急避孕的新标准。
