在一个月经周期内,投以3个剂量不同的小剂量雌孕激素复合口服避孕丸称三相性微丸避孕药。其主要优点是提高避孕效果,减少点滴出血和突破性出血的副作用。服用方法通常是从月经第一天开始,连续服用21天,然后停药7天再开始下一周期的服药。但一 In a menstrual cycle, cast a small dose of three different doses of estrogen and progesterone oral contraceptive pill that three-phase pill pellet. The main advantages are increased contraceptive effectiveness, fewer side effects of spotting and breakthrough bleeding. It is usually taken from the first day of menstruation, for 21 consecutive days and then discontinued for 7 days before beginning the next cycle of medication. But one