左炔诺孕酮（左旋18－甲基炔诺酮）的各种剂型作为常规避孕药已在临床应用几十年。近年WHO组织多中心随机临床试验将左快诺孕酮0.75mg口服2次用于紧急避孕[1]，取得良好效果。为进一步方便使用，我们探索应用1．5mg口服1次作为紧急避孕，观察其效果及对月经的影响。1治疗对象19 Various dosage forms of levonorgestrel (levonorgestrel 18) have been in clinical use for decades as conventional contraceptives. In recent years, the WHO multi-center randomized clinical trial of oral levonorgestrel 0.75mg orally 2 times for emergency contraception [1], and achieved good results. For further convenience, we explored the application of 1.5mg orally once as an emergency contraception to observe its effect and its effect on menstruation. 1 treatment 19