Menstruation menarche has changed little in the United States since the 1950s. Menstruation is the most visible phase of the menstrual cycle and its beginning is used as the marker between cycles. The first day of menstrual bleeding is the date used for the last menstrual period (LMP). The typical length of time between the first day of one period and the first day of the next is 21 to 45 days in young women, and 21 to 31 days in adults (an average of 28 days). Perimenopause is when fertility in a female declines, and menstruation occurs less regularly in
Menstrual extraction internationally. This method, another type of manual vacuum aspiration, is most often called menstrual regulation. As with ME, menstrual regulation, when desired as a method of controlling fertility, is performed very early in the menstrual cycle, earlier than a pregnancy test can be performed. One main difference between these two methods is the equipment used. While the Del Em was created such that one is able to put it together from individual pieces and it consists of three parts: the cannula with a one-way valve, a collection jar and the syringe, which are connected by plastic tubing; menstrual regulation is