MENSTRUAL CYCLE AND ITS PHASES

The menstrual cycle is a process that lasts about 28 days and is divided into 4 phases (3 + ovulation), each of which repeats incessantly during a woman's fertile years until menopause.

During pregnancy, menstruation stops and starts again after the birth. We start counting from the first day of menstruation, i.e. when we have a more or less abundant flow of blood.

- FIRST PHASE: Menstruation or menstruation (1st to 5th/7th day). Blood is the outward evidence of the presence of the cycle in a woman. It lasts from 3 to 5 days and can present itself with cramps, bloating, exhaustion and mood swings.

- SECOND PHASE: Follicular (from day 5 to day 13). These are the days between the end of the menstrual phase and the beginning of ovulation, when the production of the hormone FSH increases, whose function is to promote the growth of the follicles in the ovaries and the maturation of the eggs. Body temperature is maintained at around 36°.

FSH levels during the cycle

- THIRD PHASE: Ovulation (day 14). Luteinizing hormone (LH), stimulated by increased estrogen (estradiol) production, causes the follicle to rupture resulting in the release of the mature ovum in the ovary, which travels down the fallopian tube to the uterus and can be fertilized by spermatozoa, about day 14. During ovulation, the body temperature rises almost a 1° above the temperature of the follicular phase.

LH levels during the cycle

Oestradiol levels during the cycle

- FOURTH PHASE: Luteal (day 15 to 28). Involves decreasing estrogen levels and increasing progesterone to facilitate implantation of the egg in the uterus. If the egg is not fertilized, the follicle contracts within the ovary, progesterone levels decrease, and the endometrium is shed and eliminated through menstruation.

The luteal phase, unlike the other phases of the menstrual cycle, has the same duration for all women, so being able to understand the beginning of your luteal phase is very important if you want to calculate your fertile days based on the external signs of your menstrual cycle.

Progesterone levels during the cycle.

DID YOU KNOW THAT?

During the luteal phase, PMS (Pre-Menstrual Syndrome)develops. It is characterised by biological and psychological changes that vary greatly from one woman to another, with minor or major physical symptoms, mood swings, cravings for particular foods, insomnia and lack of interest in what one usually likes.

These symptoms fortunately stabilise soon after the onset of menstruation.