Follicular phase what is what day of the cycle (hormone norm)

A woman's menstrual cycle consists of several phases, each of which creates its own conditions for successful release of the egg from the epididymis, its advancement to the uterine cavity, fertilization and implantation into endometrium. The follicular phase is the time period starting from the first critical days, the most important for high-quality ovulation, subsequent conception and gestation.

Important information about a woman's menstrual cycle

In the female body, the organs of the reproductive system must work clearly and in a coordinated manner so that one healthy full-fledged egg is released from hundreds of follicles. In the regulation of each phase of the menstrual cycle, hormones produced by the pituitary gland, hypothalamus and ovaries are involved, systemic diseases and autoimmune problems also affect the process.

The first day of menstruation is the period from which the cycle begins. It can be short (21 days), medium (28–30 days) or long (up to 31–35 days). From the first day from the onset of bloody discharge, follicles are formed, in one of which an egg cell ready for future fertilization will mature - it is called the dominant follicle.

To understand the concept of the follicular phase, to understand what it is and on what day of the cycle it begins and how long it lasts, you need to know general information about each of the cyclic phases:

Follicular

It takes its countdown from the first day of menstruation, lasts from 7 to 21 days, depending on the individual characteristics of the body and the average duration of a woman's cycle. In the first few days, the endometrium of the uterus is actively rejected and goes out (proliferative phase), during this period active maturation of follicles occurs, one of which will later become dominant.

Ovulatory

Lasts 2-3 days, during which the most significant follicle is already clearly visible. It increases in volume and begins to produce estradiol. Ovulation takes from 7 to 10-14 days of the cycle, after which the follicle bursts, and the egg comes out of it. She retains the ability to fertilize for 24 hours.

Luteal

It starts immediately after ovulation and lasts from 10 to 14 days, if the egg has not been fertilized, it ends with the arrival of menstruation. With perfect fertilization, the corpus luteum actively develops, with the participation of which progesterone and estradiol are produced. These hormones are necessary for the full introduction of the embryo into the uterine wall.

If conception does not occur, the endometrium of the uterus is rejected due to a decrease in the amount of the hormone progesterone produced by the corpus luteum.

For the average duration of the monthly cycle, indicators of 28–35 days are taken, of which the follicular and the next, luteal phase of the cycle, occupy approximately the same time intervals. That is, with a standard 28-day cycle, ovulation occurs on day 14, when the maturation of the follicle ends and the egg is released.

These indicators can fluctuate in women between the ages of 20 and 40. More significant changes in the duration of the phases are observed in adolescents during puberty after the first menstruation and in women 5-10 years before the onset of menopause. All other failures of the cycle should be noticed by a woman for a timely visit to a gynecologist.

More about the follicular phase

The follicular or follicular phase got its name due to the formation in this time interval of follicles located in the cortical layer of the ovaries. This stage begins on the first day of menstruation due to the death of the corpus luteum due to the cessation of progesterone production. Follicle maturation is possible due to the production of follicle-stimulating hormone - FSH.

In total, 5–6 follicles develop at the same time, they are ready for the transition to a new cyclic stage. Along with the follicles, the endometrium grows - the inner uterine layer, a mass of blood vessels grows in its tissues, preparing for the adoption of the embryo when fertilization occurs. The follicular stage is characterized by the effect of not only FSH, but also other hormones:

• prolactin;
• estradiol;
• progesterone;
• luteinizing hormone - LH.

Under the influence of these substances, one or two dominant follicles are released, the rest stop their development and atrophy. Further maturation of the dominant lasts from 7 to 14 days. The duration of its growth varies up to 22 days, but in such a situation it is better for a woman to consult a doctor and find out the reasons for the lengthening of the follicular stage.

In more detail, the process of follicular growth looks like this:

• the first 5 days all follicles grow;
• on the 5-7th day, one of the components of the appendage becomes dominant;
• by 10 days, the dominant reaches 10 mm in diameter.

After 10 days from the beginning of the cycle, the dominant is clearly visible on ultrasound in the form of an echogenic circle. By the onset of ovulation, its diameter is already 1.8-2.6 cm. The volume of FSH decreases sharply, due to which the rest of the structural particles of the ovarian cortical layer inhibit development.

Endometrial phases

Together with bloody discharge during menstruation, the dead endometrial layer leaves the uterus - this is what distinguishes the follicular phase of the cycle from others. The endometrial layer changes in thickness depending on the phase - after cleansing the uterus from its remnants, it begins to grow again. Under the influence of the hormone estrogen, the tissue of the uterus is ready to accept the embryo in case of fertilization. If conception is not successful this month, the endometrium is destroyed and evacuated, and so on, cycle by cycle.

There are three phases of endometrial tissue growth:

1. Early - marked on the 5-7th day of the menstrual cycle. It is characterized by a thin endometrial layer of a pale pink hue, a small amount of vessels in the epithelium.
2. Average - fixed at 8-10 days, the epithelium is edematous and loose, the diameter increases.
3. Late - takes from 11 to 14 days of the cycle, the endometrium is covered with folds, acquires a bright pink tint, the capillaries are almost invisible.

If, after the ultrasound scan, the patient was written in the card that the endometrium is at a certain stage of proliferation, do not be alarmed. This is simply a statement of at what point in the cycle the diagnostics were carried out.

Basal temperature in the follicular phase

In each phase of the monthly cycle, the body behaves in a certain way, showing symptoms, looking closely at which a woman who wants to have a child can calculate the onset of the most auspicious days.

One of the methods how to calculate when the follicular stage of the menstrual cycle ends and the ovulatory stage comes - measuring the basal temperature.

At this stage, the temperature is 36.7–37 ° C, during ovulation it rises to 37.2 ° C. A further increase in indicators (up to 37.5 ° C) indicates the onset of the luteal phase of the cycle. To measure basal temperature correctly, it is important to follow several rules:

1. The measurement is made in the morning, without getting out of bed and without making sudden movements, in the rectum.
2. It is advisable not to change the thermometer during daily measurements.
3. Before fixing the basal temperature, it is important to exclude intimate acts for at least 6 hours.

Before the onset of ovulation, the temperature in the rectum will be in the range of 36.7-37 ° C due to the fact that the level of progesterone in the blood is low. With the subsequent production of this hormone by the corpus luteum, the temperature gradually begins to rise. If pregnancy has occurred, the thermometer readings under the influence of progesterone will remain elevated for a long time. In response to hormonal effects, the thickness of the endometrium also increases, and blood supply increases inside the tissues.

Follicular stage signs

During the follicular phase of the menstrual cycle, a dominant follicle is formed - when it enters the ovulation phase, it begins to produce estrogen. Thanks to the growth of this hormone, the thickness of the endometrium increases, which prepares for the adoption of the embryo. Under the influence of LH, also synthesized by the follicle, ovulation occurs, and the dominant turns into a sac containing a mature egg.

An increase in LH levels is necessary for rupture of the sac, for the release of the egg outside and the start of its movement along the fallopian tube. Pushed by the hairy epithelium of the fallopian tube, the egg moves towards the uterus. If the fertilization process does not take place, it will dissolve in the mucous membrane.

Ovulation for most women goes unnoticed, but many note the occurrence of painful sensations when the rupture of the dominant sac and the movement of the egg through the tube is recorded. And if it is not problematic to recognize ovulation, then the follicular stage manifests itself as rather erased symptoms:

• softness of the mammary glands;
• discharge from the cervical canal of a mucous mass, similar in consistency to glue;
• discharge of a yellowish tint, noted in the middle of the cycle - a suitable environment for continued activity
• sperm and increase the chances of successful conception.

In the follicular phase, a woman has clear mucous discharge, but the vaginal environment is dry.

Immediately after the onset of ovulation, the luteal phase is diagnosed - it lasts 10-14 days. After the vesicle containing the mature egg has ruptured, an increased accumulation of lipids and lutein is triggered. Under the influence of substances, the vesicle turns into a corpus luteum, producing estradiol, progesterone and androgens.

Normal hormone levels

To determine the norm of hormones corresponding to the follicular phase, it is necessary to donate blood 3-5 days from the onset of menstruation. The main sex hormones present in the blood of a woman in the proliferation phase and their rates are shown in the table.

Cycle phases	FSH	LH	estradiol	progesterone	testosterone
Follicular	1,1–11	1,1–8,8	5–53	0,32–2,23	0,1–1,1
Ovulatory	4,9–20,4	13,2–72	90–299	0,48–9,41	0,1–1,1
Luteal	1,1–9,5	0,9–14,4	11–116	6,99–56,43	0,1–1,1
Menopause	31–130	18,6–72	5–46	Less than 0.64	1,7–5,2

What does each of the hormones produced by the female body mean for the health of the reproductive system:

1. FSH - provides the follicles with nutrients during the follicular phase, correctly forms the egg.
2. LH - hormone values ​​that are outside the normal range (above and below) indicate a malfunction in the pituitary gland or the presence of neoplasms in the area of ​​the appendages.
3. Estradiol is essential for the supply of vitamins to follicular tissue and for the growth of the endometrium.
4. Progesterone - supports the onset of pregnancy.
5. Prolactin - required for high-quality production of breast milk during lactation and breastfeeding.

It is during the follicular phase that blood tests are recommended to determine hormone levels. Due to the accuracy of the indicators in 3-5 days, the specialist will be able to suspect the disease based on the existing deviations, refer the patient for further examination and select the treatment tactics.

Follicular phase lengthening

Sometimes during the examination, the woman is diagnosed with a long follicular phase. The causes of cycle disorders must be identified in order to avoid complications that threaten infertility. In such a situation, when the dominant matures for too long, ovulation does not occur, as a result, there is no conception. The reasons may be polycystic ovary disease, thickening of the walls of the appendages. With a long phase, a blood test for hormone levels is necessary, followed by treatment, including drugs to stimulate the ovulatory process.

Knowledge about the duration of each of the phases of the monthly cycle and their characteristics will help a woman who wants to get pregnant to prepare for this process and not miss the days favorable for conception. It is important to understand that each organism is individual, which means that for some patients a slightly lengthened follicular stage is normal, and for others it is shortened. If it is found by inspection that the indicators go beyond the normal range, you must seek help from a qualified specialist.

Sources:
https://www.baby.ru/wiki/kak-rasscitat-follikularnuu-fazu-i-opredelit-ovulaciu/
https://www.cironline.ru/articles/92597/
https://www.syl.ru/article/160415/new_follikulyarnaya-faza-tsikla
https://ru.wikipedia.org/wiki/
https://www.msdmanuals.com/ru/
https://www.kp.ru/guide/tsikl-mesjachnykh.html