Menstrual cycle The first period usually begins between twelve and fifteen years of age, a point in time known as menarche. They may occasionally start as early as eight, and this onset may still be normal. The average age of the first period is generally later in the developing world and earlier in developed world. 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 35 days in adults (an average of 28 days). Menstruation stops occurring after menopause which usually occurs
Centre for Menstrual Cycle and Ovulation Research stated vision was to 'reframe scientific knowledge of the menstrual cycle and ovulation in a woman-centered context.' CeMCOR is now located at Vancouver General Hospital in the Gordon and Leslie Diamond Health Care Centre. Staff includes 15 clinicians and 9 trainees. It is guided by both a Community Advisory Council and a Scientific Advisory Council composed of endocrinologists, epidemiologists, gynecologists, nutritionists, psychologists, and sociologists. CeMCOR published over 50 scientific papers in its first 10 years, as well as 4 books. Areas of research include menstruation and ovulation, bone health, premenopausal breast cancer, polycystic ovary syndrome (PCOS), and perimenopause. CeMCOR has