Gynecological autonomy (2/3): menstrual cycle and hormones

• cycle menstruel
• déséquilibres hormonaux

Produce a mature egg so that it can be fertilized when it leaves the ovary

Produce female hormones (estrogen and progesterone) to mature the egg and expel it (estrogen) and then maintain "nutrition" of the possible fertilized egg (progesterone) while the placenta develops.

The Follicular Phase : It begins on the first day of menstruation and ends at the time of ovulation. We are talking about an average duration of 14 days, but it varies from one woman to another. During this phase, the objective is to mature the egg and then release it. There are several follicles (follicle: the "house" of the egg, where it develops - take a look at the first image to better understand) that grow, but only one of them will be selected to then be expelled at the time of ovulation.

Ovulation : the expulsion of the egg from the follicle and therefore from the ovary to the fallopian tubes takes place around day 14 of a 28-day cycle, although we know that this is "theoretical", because each woman and each cycle can vary.

The Luteal Phase : The part where the egg was contained, so the follicle must undergo a transformation once the egg has left it, then it will transform into what is called " the corpus luteum ", which will produce progesterone in order to induce the implantation of the fertilized egg in the uterus and keep it "nourished" while the placenta forms. If the egg is not fertilized by a sperm, then this corpus luteum degenerates around day 24-28 of the cycle to give rise to menstruation and start the cycle again.

To welcome a fertilized egg and provide it with a favorable environment for development.

Preovulatory phase (Follicular or estrogenic) : from the first day of menstruation until bleeding stops (3-7 days depending on each woman), the blood is proof that the part of the endometrium that had prepared itself to accommodate a possible pregnancy is being eliminated. Once the elimination is finished (around day 7 to approximately day 14), the endometrium prepares again for ovulation and begins to thicken.

Ovulation : It continues to thicken.

Post-ovulatory phase (Luteal or Progestational): during this phase, the endometrium reaches maturity in order to accommodate the fertilized egg, it begins to secrete a type of sugar (glycogen) in order to "feed" the fertilized egg. If it implants (Secretory phase) around day 20-24, it reaches the "ideal" peak of maturity for implantation. If there is no implantation , then it begins to necrotize and therefore to detach, the period arrives and the cycle begins again.

Preovulatory phase (Follicular or estrogenic) : once the period is over, the cervix is ​​hard or firm, it is lower in the vagina (easier to find with the fingers), it is closed by thick and sometimes scanty mucus (the cervix is ​​said to be "dry") which seeks to prevent the passage of spermatozoa.

Ovulatory phase: as ovulation approaches, the cervix becomes softer, a little more open and higher in the vagina. The mucus begins to be more and more important and changes from whitish to transparent and more fluid (a bit like egg white), we then feel the cervix "wet".

Post-ovulatory phase (Luteal or progestin): the cervix becomes hard again, closes and descends, the mucus is thick again and therefore gives a sensation of "dry" cervix. Just before the period, you can feel the cervix lower and more open, if you taste the mucus, it will have a "metallic" taste (iron = blood) ;) this announces the arrival of the period.

FSH - Follicle Stimulating Hormone - as its name refers, it will instruct the ovaries to start stimulating the growth of follicles (the small pockets where the egg develops) and will stimulate the production of estrogen in the ovary.

LH - Luteinizing Hormone - it will participate in the maturation of follicles in the ovary, its peak will trigger ovulation , it will regulate the production of estrogen and progesterone after ovulation .

Estrogens : They increase at puberty, remain stable throughout the fertile years and decrease at menopause. They are produced mainly in the ovary , but also in the adrenal glands (this information is important to understand the role of stress in hormonal imbalances). Levels will vary with the cycle. Their functions are:

• Developing the female sexual apparatus
• Developing sexual characteristics at puberty
• Ensure follicle growth in the ovary
• The increase in estrogen in the blood will trigger the secretion of the hormone LH which will then trigger ovulation .
• Induce endometrial development during the first part of the cycle
• It is responsible for the production of more fluid cervical mucus (egg white)

Progesterone : This is a steroid hormone (formed from cholesterol, important information to then understand the relationship between the amount of fatty tissue in the body and hormonal imbalance ). It is produced in the ovaries , but also in the placenta , liver and adrenal glands . It begins to be produced during puberty and decreases at the time of menopause. Their functions:

• Prepare the endometrium for nidation or implantation .
• Make the muscles of the uterus more flexible .
• Thicken cervical mucus to produce a "plug" in case of pregnancy and to be able to prevent anything from entering the uterus (therefore "protects baby").
• Stimulate prolactin - lactation hormone.
• When it decreases, it induces menstruation or detachment of the endometrium (important information to then understand the relationship between this hormone and miscarriages).

During menstruation (Day 1 to Day 7 or so): Estrogen levels are at their lowest, so the pituitary gland picks up the message and sends out more FSH (positive feedback) saying, "Let's make our eggs grow, because we don't have any left!"

End of period until ovulation : the pituitary gland continues to send more and more FSH and as a result the ovary says to itself: "let's produce more estrogen to make our eggs grow!". It goes up and up until it reaches a peak , this is the message that the ovary sends to the pituitary gland to say that the egg is ready, a bit like the oven doorbell ;) At that moment, the pituitary gland stops sending FSH and sends a good dose of LH , the message to say: "release the egg!"

Ovulation (around day 14) - when LH is at its peak, the egg (ovum) is released , and everyone keeps their fingers crossed that it finds "the right sperm".

Post-ovulation until day 21 - this LH surge and the rupture of the follicle (the pocket where the egg was contained) are the message to say that we need to prepare the "cradle" for the egg, because it has been released and will possibly be fertilized in the coming days. Progesterone begins to rise in order to prepare the endometrium to receive and nourish this egg.

Day 21 to 24 - everyone is waiting for the phone call confirming fertilization, because the "cradle" ( endometrium) is ready , tick-tock, tick-tock...

Day 24 to 28 - no phone call no fertilization, progesterone drops , uterus sheds cradle cap (endometrium) and period arrives.