Women do not talk about menstruation other than to comment if it hurts more or less, if it lasts 3 or 5 days, or about the abundance of our bleeding; In addition, depending on the age, we will exchange information about the methods we use to absorb (compresses, tampons, natural sponges) or retain (menstrual cup) the bleeding, topic - by the way - interesting in itself, which deserves to be expanded. But menstruation is part of a cycle, which on average lasts about 28 days, and it is also part of our feminine condition, why reduce it to such trivial issues as pain?
Today I'll begin to tell you about the menstrual cycle, focusing on the first phase. In reality, according to information sources, it isn't exactly made up of two phases, but rather these, in turn, are made up of others. I'll try to be as explicit and concrete as possible, so that the information is clear. The reason I want to talk to you about this topic is that the menstrual cycle has a reproductive purpose (conceiving a baby), but it also affects how we feel. Although stereotypes like the one that points to menstruation as a 'punishment from Nature' are still accepted, we can see it as a health marker that allows us to understand how our body works.
As I said, the cycle usually lasts 28 days, but it is also accepted that it lasts between 21 and 35 days, without this being abnormal. It begins on the first day of menstruation, during which the body is freed from the endometrium (lining of the uterus) and the blood leaves the body through a small opening in the cervix, and then passes through the vagina. It is worth mentioning that at two or three years after menarche (first rule), cycles are usually irregular; as they are from the age of 40/45, until a woman 'enters' menopause. Más Medicina tells us about the cycles after pregnancy and childbirth, and we'll tell you more about them later.
Follicular maturation phase: selection of the ovum
From the outset, tell you that everything is the product of the action of a series of hormones, if you keep reading you will understand. First They help the uterus expel the endometrium, causing contractions that cause pain or discomfort. During the first few days, the follicle-stimulating (FSH) secreted by the pituitary gland, stimulates the ovaries to 'produce' eggs: in each follicle there is an immature egg, and some of them are stimulated to generate estrogen, whose level rises with the growth of the follicles.
It is the moment when the dominant follicle causes your egg to mature (there are exceptional cases in which more than one follicle matures and if fertilization occurs, it results in multiple pregnancies). This stage, known as follicular or preovulatory phase, covers the period from menstruation to ovulation, and is the most variable in cycle length.
At that moment, the dominant follicle approaches the surface of the ovary with its egg inside, and later, with advanced development, occupies half of it. This is when we call it the 'Graafian' or preovulatory phase. With complete maturation, the oocyte/ovum is released from the oocyte and begins its journey through the fallopian tube. The luteal phase then begins, which we will discuss tomorrow.
What happens during the follicular phase in the ovaries and uterus?
In the ovary, the FSH induces the growth of several follicles, but one gains the advantage and becomes dominant; the rest stop their development due to atresiaThis follicle produces increasing amounts of estradiol, until reaching levels that trigger a discharge of LH (LH surge), a signal that triggers ovulation and marks the end of the follicular phase.
In the uterus, while we bleed, the endometrium is shed; then, under the effect of estrogen, the mucosa enters proliferative phase and regenerates from its basal layer. In parallel, the cervical mucus It evolves from sparse and dense to more abundant, elastic and transparent (egg white type), a change that facilitates the passage and sperm survival.
It is common to think that we ovulate around day 14, but each woman has a different menstrual cycle, that's why it is also variable. When ovulating you may feel sharp pains (mittelschmerz), although this is not always the case, nor even in all the cycles of the same person. For example, estrogen helps the endometrium to be covered with nutrients, and you will not notice this, but Does cervical mucus sound familiar to you? What comes out of the vagina on those days? It's usually thin and clear or cloudy white, and is good for sperm.
Duration of the follicular phase and what can modify it
In a 28-day cycle, the follicular phase lasts about 14 days, of which the first 3 to 6 correspond to menstruation. However, it is the most variable phase of the cycle: if your cycle shortens or lengthens, it is almost always because this phase has changed (the luteal phase is usually more stable).
Factors like Stress, time zone changes due to travel, sudden weight changes, strenuous physical exercise or certain hormonal imbalances, can alter the coordination of the hypothalamic-pituitary-ovarian axis and modify the duration of this stage. If the cycles become unpredictable or clearly irregular, it is advisable consult a specialist.
Signs of fertility and ways to identify ovulation
For many women, combining methods increases accuracySome useful strategies are:
- Menstrual calendar: Recording multiple cycles helps estimate your fertile window, knowing that ovulation usually occurs 12-16 days before of the following rule.
- Observation of cervical mucus: when you turn around clear, elastic and stringy, ovulation is approaching.
- Basal temperature: remains lower in the follicular phase and rises after ovulation due to the effect of progesterone; it is useful for confirm that already happened.
- Ovulation test (LH): detect the LH surge in urine, anticipating ovulation in the following 24-36 hours.
Remember that sperm can live 3-5 days in the reproductive tract, while the egg remains fertilizable 12-24 horas. Therefore, having sex in the days before the LH surge increases the chances of pregnancy.
Tests and clinical monitoring of follicular maturation
In consultation, follicular development is assessed by transvaginal ultrasound (the growth of follicles is observed) and hormonal profiles (FSH, LH, estradiol and later progesterone). The test FSH It is usually done beginning of the cycle (usually days 3-5) to better interpret ovarian function in that context.
When the dominant follicle reaches a preovulatory size, close to the 18 mm (may vary), the LH peak is approaching. In assisted reproduction, this information allows interventions to be synchronized. If there are persistent alterations (for example, polycystic ovary syndrome, anovulation, or very irregular cycles), gynecological assessment guides treatment.
Follicular maturation in assisted reproduction
The follicular phase is key in techniques such as egg donation or in vitro fertilization. Under ultrasound and hormonal control, the growth of several follicles is stimulated; when they reach the appropriate size, the implantation is scheduled. follicular puncture to retrieve oocytes. Understand how follicles mature and how they respond to FSH helps to optimize the process and adjust protocols according to each patient.
Finally, I remind you that this first phase of the menstrual cycle is called follicular maturation, and includes the menstrual cycle (which will last between 3 and 7 days). The duration of this phase is about 14 days on average, that is, until the egg leaves the ovary that has housed it, and make way for the next. It is a fascinating process, and I think it's important that we get to know it.
Image — TipsTimesAdmin.
Understanding the follicular phase beyond bleeding allows for interpretation symptom, anticipate the fertile window and detect possible issues in time hormonal imbalancesObserving the progress of your mucus, using an LH test, and charting your cycle gives you a practical overview of your ovulation period. If you notice any notable changes in duration, amount of bleeding, or discomfort, your healthcare professional can support you with personalized assessment and follow-up.