Gemzell-Danielsson K, Swahn M L, Svalander P, Bygdeman M
Department of Obstetrics and Gynaecology, Karolinska Hospital, Stockholm, Sweden.
Hum Reprod. 1993 Jun;8(6):870-3. doi: 10.1093/oxfordjournals.humrep.a138157.
Mifepristone (RU 486) is an antiprogestin which interacts with progesterone at the receptor level. Administration of mifepristone immediately after ovulation does not upset the menstrual cycle. However, the maturation and function of the endometrium is inhibited and uterine contractility is changed. To test if these effects are sufficient to prevent implantation, 21 women agreed to use one single treatment with 200 mg mifepristone on day luteinizing hormone (LH) + 2 monthly as their only contraceptive method. The women were treated for 1-12 months. The time of the LH peak was determined in the urine by the women themselves using a rapid LH test (Ovu-quick, Organon). The overall number of cycles studied was 169. In 12 cycles the women were unable to detect the LH peak. In these cycles no treatment was given and the women advised to use barrier methods during the time to menstruation. The remaining 157 cycles with a detectable LH peak were all ovulatory based on plasma progesterone measurement. One pregnancy occurred. On the basis of the time of the LH peak, it was retrospectively calculated that in 124 cycles at least one act of intercourse occurred during the period 3 days before to 1 day after ovulation. The probability of pregnancy in this period of the menstrual cycle is thus 0.008. The women did not complain of any treatment-related side-effects apart from slight bleeding for 2-3 days starting a few days after the day of treatment in 35% of the cycles.(ABSTRACT TRUNCATED AT 250 WORDS)
米非司酮（RU 486）是一种抗孕激素，它在受体水平与孕酮相互作用。排卵后立即服用米非司酮不会扰乱月经周期。然而，子宫内膜的成熟和功能会受到抑制，子宫收缩性也会改变。为了测试这些作用是否足以防止着床，21名女性同意每月在黄体生成素（LH）+2日单次服用200毫克米非司酮作为唯一的避孕方法。这些女性接受了1至12个月的治疗。女性自己使用快速LH检测法（奥鲁快，欧加农公司）在尿液中测定LH峰值时间。总共研究了169个周期。在12个周期中，女性未能检测到LH峰值。在这些周期中未进行治疗，并建议女性在下次月经来潮前使用屏障避孕法。根据血浆孕酮测量，其余157个可检测到LH峰值的周期均为排卵周期。发生了1次妊娠。根据LH峰值时间进行回顾性计算，在124个周期中，至少有一次性交发生在排卵前3天至排卵后1天期间。因此，月经周期这一时期的妊娠概率为0.008。除了35%的周期在治疗后几天开始出现2至3天的轻微出血外，女性未抱怨任何与治疗相关的副作用。（摘要截短至250字）
