Periods are characterized by the loss of the endometrium , the lining of the uterus, accompanied by bleeding. They occur on average every month, except during pregnancy and after menopause. However, only 10 to 15% of women have a cycle that lasts exactly 28 days , with menstrual cycles lasting on average between 24 and 38 days. And in 20% of women, cycles are irregular! Especially during the first years of menstruation but also before menopause.
We often talk about periods and the "menstrual cycle", and a little less about the cycles that follow one another during these hormonal changes. Here's how to see things more clearly!
1/ The follicular phase (before the release of the egg, begins with the menstrual phase)
At the beginning of the menstrual cycle, the lining of the uterus thickens to prepare for a possible embryo. If fertilization does not occur, the hormones estrogen and progesterone drop , and the outer layer of the endometrium breaks down, leading to menstruation . The follicular phase lasts 13 to 14 days, and is the one that varies the most (it often shortens as menopause approaches). This phase 1 ends when luteinizing hormone rises sharply, triggering ovulation and the start of phase 2.
2/ The ovulation phase (release of the egg)
The ovulatory phase begins when luteinizing hormone increases, causing the egg to be released 16 to 32 hours later. The egg can be fertilized within 12 hours of this release and sperm can survive for up to 3 to 5 days... creating a fertile window of 6 days around ovulation. During the ovulation phase, some women experience mild abdominal pain called mittelschmerz "middle pain", related to the release of the egg.
3/ The luteal phase (after the release of the egg)
The luteal phase begins after ovulation and lasts about 14 days, unless fertilization occurs. During this time, the follicle becomes the corpus luteum , which produces progesterone to prepare the uterus for a possible pregnancy.
This hormone thickens the endometrium and cervical mucus, also slightly increasing body temperature. If the egg is not fertilized, the corpus luteum disappears, hormone levels drop, and menstruation begins .
In case of pregnancy, the hormone hCG maintains the production of progesterone, detectable in pregnancy tests.
Did you know that these cycles influence your health? Here are some tips for living in harmony with your menstrual cycle.
