黄体早期服用低剂量米非司酮作为妇女常规避孕方法的初步研究

目的:探讨米非司酮用于妇女常规避孕的可行方法。方法:共74例自愿受试人员,于规律月经第15日开始,口服米非司酮5 mg,按疗程递减顺序分别为A组(研究Ⅰ期)每日1次连服4天,B组(研究Ⅱ期)每日1次连服3天,C组(研究Ⅲ期)隔日1次共服2天,观察避孕效果及月经周期改变情况,对可能月经推迟3天及以上者行尿HCG、B超等检查排除早孕。结果:A组43例受试125周期,122例次月经如期来临,3例次月经推迟6~9天,尿HCG、B超等检查阴性,有效率100.0%,月经正常率97.6%。B组68例(A组43例+新入受试25例)受试286周期,282例次月经如期来临,4例次月经推迟5~8天,尿HCG、B超等检查阴性,有效率100.0%,月经正常率98.6%。C组6例(新入受试人员)受试12周期,9例次月经推迟6~9天,尿HCG、B超等检查阴性,有效率100.0%,月经正常率25.0%。A、B两组共获411受试周期,避孕有效率均达100.0%,月经正常率98.3%;C组月经周期正常率显著低于A、B组(P0.01),研究暂时终止。A、B两组避孕效果及对月经的影响差异无统计学意义(P0.05)。结论:黄体早期(内膜分泌期早期)阶段短程、小剂量应用米非司酮有较好的避孕效果,且对月经周期无明显的影响,月经规律者可用于每月的常规性避孕。初步研究认为较佳的剂量-时效关系为米非司酮5mg/d连用3天。

A Preliminary Study on the Use of Low Doses of Mifepristone in the Early Luteal Phase as a Routine Contraceptive for Women

Objective:To explore the feasible method of mifepristone for routine contraception in women.Methods:74 women volunteered to join the study,who started on the 15th day of a regular menstrual cycle,oral mifepristone 5mg,according to the course of descending order respectively for group A:5mg daily for 4 days(5mg/d ×4d);group B:5mg daily for 3 days(5 mg/×3d);group C:5mg every other day for 2 days(5 mg/qod ×2d),observed contraceptive effect and menstrual cycle changes,the menstruation to defer 3 days and above,HCG and B ultrasonic examination to exclude pregnancy.Results:In group A,43 subjects with 125 test cycles,122 cycles of menstruation coming as scheduled,3 cycles of menstruation delayed 6-9 days,HCG and B ultrasonic examination negative,result of conception control 100.0％,normal menstrual cycle rate 97.6％;group B:68subjects(group A 43 cases + 25 cases of new in cases) 286 test cycles,282 cases coming as scheduled,4 cases delayed 5-8 days,HCG,B ultrasonic examination was negative,result of conception control 100.0％,normal menstruation rate 98.6％;group C:6 subjects(all new in) 12 cycles,9 cases of menstruation delayed 6-9 days,HCG and B ultrasonic examination negative,result of conception control 100.0％,normal menstruation rate was 25.0％.A,B two groups received 411 test cycles,contraceptive effect was 100.0％,normal menstrual cycle rate 98.3％,the menstrual cycle was no obvious change;in group C normal menstrual cycle rate was significantly lower than that of A and B group(P＜0.01).The experimental group C terminated temporary.The difference of contraceptive effect and normal menstrual cycle rate in A,B two groups was not statistically significant(P ＞0.05).Conclusions:In early luteal phase(endometrial secretory stage) application with short-range low-dose mifepristone has good contraception effect,and has no obvious disturbance on the menstrual cycle and menstrual regularity,it can be used for monthly whole menstrual cycle contraceptive.The preliminary studies suggest a better dose-time-effect relationship for mifepristone 5mg/d 3 days.