Generality
The fertile period is a phase of the menstrual cycle during which a woman has the possibility of becoming pregnant .
In general, the most favorable days for conception are 6 and coincide with ovulation and with the period immediately preceding it. During the ovulatory phase of the menstrual cycle, in fact, the egg cell (also called oocyte or oocyte ) undergoes maturation and is released into the uterine tube where, if it meets the spermatozoa, it can be fertilized .
The time that elapses from the onset of menstruation to ovulation is on average 14 days, but there are individual variations that it is important to consider in calculating the fertile period. Not all women have regular menstrual cycles.
After this premise, it is clear that knowing your own body's rhythms and times is very important when trying to have a baby or wanting to avoid a pregnancy .
In addition to paying attention to your menstrual cycle with the calendar in hand, the correct interpretation of a series of signals sent by our body (such as changes in cervical mucus and an increase in basal temperature after ovulation) can help:
- Identify the fertile period;
- Understand when conception is most likely.
What's this
What is meant by Fertile Period?
The fertile period is the phase of the menstrual cycle, in which the chances of beginning a pregnancy are greater. In other words, it is the time interval in which ovulation comes to completion and the spermatozoon (male gamete) has a higher probability of fertilizing the egg cell (female gamete).
Phases of the menstrual cycle
How does the menstrual cycle work?
The starting point for calculating the fertile period as accurately as possible is the knowledge of one's own menstrual cycle:
- What is the menstrual cycle? During the reproductive life of a woman, the menstrual cycle is a recurrent process, characterized by the delicate chain of physiological events, directly related to fertility. Each month, we determine:
- Changes in the structure and function of the ovaries and uterus;
- Secretion of ovarian, hypothalamic and pituitary hormones.
- What is it for? The fundamental purpose of the menstrual cycle consists in bringing the egg cell (female gamete) to maturity and preparing an "environment" suitable for its eventual plant . The physiological processes that follow one another during this period predispose, therefore, to the beginning of a possible pregnancy, in the event that the oocyte was fertilized by a sperm of male origin. The menstrual cycle occurs at regular intervals, on average every 28 days, that is from the 1st day of a period to the day before the start of the next flow. However, a certain individual variability should be considered normal.
To remember
All the changes that occur during the menstrual cycle are used to prepare the organism for possible fertilization and pregnancy, therefore they are fundamental for achieving the ultimate function of the reproductive system: the CREATION OF A NEW LIFE .
Rhythm and Length of the menstrual cycle
The menstrual cycle is repeated cyclically every month, from puberty to menopause (fertile period or, more correctly, fertile age ).
The menstrual cycle is considered the period of time that goes from the 1st day of a menstruation to the day before the start of the next menstruation.
The interval between the start of two successive menses is generally 28 days . However, a certain variability has to be considered normal: the duration of menstrual cycles can usually go from 25 to 36 days.
Diary of the menstrual cycle
A good habit to adopt to clearly identify the fertile days on the calendar is to record the beginning of menstruation monthly .
The menstrual cycle is considered the period of time that goes from the 1st day of a period to the day before the start of the next flow.
In this way, you will have a more precise idea about the duration and regularity of your cycle, and it will be easier to calculate fertile days .
To learn more: Menstrual calendar: A Cosa Serve? When is it useful? »Not to be confused: menstruation and menstrual cycle
In common parlance, the term "menstrual cycle" is often used to indicate menstruation, ie the loss of blood that occurs every month and lasts, on average, from 3 to 7 days.
In reality:
- The MESTRUAL CYCLE coincides with the time interval between a menstrual period and the next one.
- MESTRUAZIONI consist of the exfoliation of the mucosa that covers the inner wall of the uterus (endometrium), accompanied by a variable loss of blood through the vagina. Menstruation therefore occurs with a regular frequency and with fairly constant duration and quantity characteristics.
Fertile Period: Ovulation
Ovulatory phase: which days coincide with the Fertile Period?
The moment of the menstrual cycle in which the woman is fertile is that of the OVULATION, that is the one in which the egg cell is released from the ovarian follicle and is captured by the fimbriae, or the mobile ends of the fallopian tubes, to be induced to cross them. Just in the tube it will, following the encounter with the male spermatozoa, the possible fertilization .
Ovulation usually occurs 14 days before the start of the new menstrual cycle; the most fertile days coincide with those preceding this phase and with the very moment in which the oocyte enters the fallopian tube and begins its journey to reach the uterus.
Ovulation is stimulated by the peak levels of estrogen and luteinizing hormone (LH), produced by the pituitary gland.
To learn more: Ovulation and Conception »The journey of the egg from the ovary to the uterus
The egg cell (ie the female gamete) moves slowly along the ovarian tube, pushed by the peristaltic waves produced by the smooth muscles of the tubular walls.
An unfertilized oocyte lives about 72 hours after being expelled from the follicle, but its ability to be fertilized by a sperm lasts only half of this time; therefore, fertilization, if it occurs, takes place in the tuba.
- If the oocyte is fertilized, the fertilized egg cell (called blastula) implants in the endometrium 3 or 4 days after reaching the uterus, that is, 6-7 days after fertilization.
- If it is not fertilized, the oocyte dies and is eliminated with the next menstruation.
Fertile Age: how long does it last?
Unlike male spermatogenesis (which can last for an almost indeterminate time, from puberty onwards), ovarian activity and the fertile female season normally end around the average age of 50, upon reaching MENOPAUSA .
Women produce, in fact, only a limited number of egg cells in their life, until the follicles in the ovaries become less sensitive to hormonal signals that induce the maturation of primary oocytes.
Fertile Days: Which and How many are
Pre-Ovulatory Phase: When Does the Fertile Period Begin?
In each cycle, the most favorable days for conception coincide with ovulation and the period preceding it. Usually, if the woman has regular menstruation, this phase is placed 14 days before the start of the next menstrual flow, then in the middle of the cycle every 28 days.
Knowing exactly the day when ovulation occurs means increasing the chances of getting pregnant or avoiding unwanted pregnancies.
Fertile Period: what happens Before Ovulation?
The period preceding ovulation "prepares" the fertile phase, giving rise to a sequence of events that ensures the maturation of the follicle destined to ovulate.
In response to the low concentration of estrogens, the hypothalamus secretes the GnRH hormone ; this causes the pituitary gland to produce the follicle-stimulating hormone ( FSH ), which stimulates the maturation of a dominant follicle, containing an egg cell ( oocyte ) destined to be fertilized. At the same time, the increasing levels of estrogen in the body cause thickening of the uterine wall, through the accumulation of blood and nutrients (in this way, the fertilized egg cell will have the necessary support for its growth).
Around the middle of the cycle, when the maturation is complete, estradiol and luteinizing hormone ( LH ) stimulate the breakdown of the follicle and the egg cell is released into the fallopian tube, through which it heads towards the uterus. This moment coincides with the OVULATION and lasts about 24 hours . However, the period in which it is possible to conceive is broader, considering that spermatozoa can remain viable for about 72-96 hours within the female genital tract and come into contact with the egg cell.
The so-called corpus luteum, which produces progesterone, is formed from the remains of the follicle that housed the oocyte. This hormone is important as it transforms the endometrium (ie the inner lining of the uterus) from proliferative to secretive (in practice, progesterone makes the uterine cavity more welcoming for embryo implantation).
Any sexual intercourse within five days of ovulation may therefore result in the fertilization of the egg cell. Outside this "window", however, a pregnancy is less likely.
Variables to consider
Fertile Period: if the menstrual cycle is long or short
When you have a regular cycle of 28 days, you should expect ovulation in the middle of the cycle, about 14 days before the next period.
To remember
If the menstrual cycle is repeated regularly every 28 days, ovulation will be around the 14th day (or 14 days before the next menstruation) and the "fertile window" will start on the 10th day. NOTE : this is an illustrative reasoning and it is not possible to know with extreme certainty if the menstrual flow following ovulation will really arrive at the 28th day (in other words, it is not said that the cycle always occurs with the same interval of days ).
However, if the menstrual cycle is longer or, on the contrary, shorter, the question changes. It is important to know that:
- The first phase of the menstrual cycle (estrogen) is variable and can undergo large oscillations;
- The second phase (progestin) is more constant and lasts an average of 14 days.
Even if the duration of the menstrual cycle is different from the average of 28 days, therefore, the fertile period will always be around 14 days before the arrival of menstruation and in the 4-5 preceding it.
To be clear:
- In a 35-day cycle, ovulation should occur on the 21st day after the end of menstruation and the "fertile window" will start on the 17th day;
- In the case of shorter cycles, which appear, for example, every 21 days, ovulation should occur on the 7th day and the "fertile window" should start on the 3rd day.
Fertile Period: if the menstrual cycle is irregular
For some women, with a very irregular cycle that varies from month to month (so to speak, with menstruation that never occurs with the same interval of days), these theoretical calculations cannot be applied.
In such cases, the fertile period will be more difficult to recognize; however, it is possible to resort to other methods, such as evaluating the signals sent by our body (eg modifications of the cervical mucus) or resorting to ovulation tests .
How to recognize it
Fertile Period: which Signals can the body send?
During ovulation the woman's body changes, as it prepares for possible fertilization and consequent pregnancy.
In addition to the appearance of more abundant, transparent and stringy vaginal discharge, other symptoms may occur during the ovulatory period, such as:
- Swelling or pain in the menstrual-like lower abdomen ;
- Breast tension ;
- Greater sexual desire ;
- Sudden changes in mood (anxiety, nervousness, euphoria, etc.);
- Increased appetite .
Furthermore, the rapid hormonal changes that occur during ovulation can cause, in some cases, a slight bleeding in the middle of the cycle ( spotting ), to be considered physiological.
Unfortunately, for many women, these manifestations are not so obvious.
How to recognize the most fertile days
To identify exactly the fertile period, multiple methods can be used.
These include:
- The prediction of when ovulation will occur with the calendar;
- The daily measurement of basal temperature;
- Evaluation of other signs, such as changes in vaginal and cervical secretions.
When you want to get pregnant
In case of difficulty in establishing the fertile period, in order to optimize the possibility of conceiving, it is advisable to have sexual relations every 2 or 3 days .
How to calculate it
Fertile Period: Calendar Method
The calendar method, also known as the Ogino-Knaus method, consists of the prediction of the fertile period based on the date on which menstruation appeared.
The fertile interval during the menstrual cycle is calculated by subtracting 18 days from the duration of the shortest of the 12 previous cycles and 11 days from the longest. For example, if the cycle varies between 26 and 29 days, conception can occur from the 8th to the 18th day of each cycle.
With wider variations in the duration of cycles, the period in which it is possible to try to have a child is greater.
It should be pointed out that the calendar method is often inaccurate and susceptible to error, even for women who have regular menstrual cycles. Ovulation can occur, in fact, before or after the scheduled day, rendering the simple numerical calculation vain.
Basal temperature: how the Fertile Period is identified
To identify the fertile period, a widely used system provides for the daily measurement of the basal temperature . This parameter, in fact, increases after ovulation of about 0.2-0.5 ° C, usually above 37 ° C, due to the effect of progesterone (hormone produced by the corpus luteum in the ovary) and remains constant for some days, before the next menstruation. Observing these data, moreover, it can be found that the rise in temperature is preceded by a slight decrease in the same.
By recording the values on a chart or on a table for a few months, it is possible to understand which days coincide with ovulation, therefore with the fertile period.
The basal temperature must be measured in the morning, at approximately the same time, before getting out of bed, introducing a thermometer in the vagina for a few minutes.
The last lowest value, recorded before the increase in the basal temperature, corresponds to the day of ovulation. Unfortunately, this parameter is influenced by various factors, such as fever and intake of certain drugs, which can compromise the reliability of the method in calculating the fertile period.
"Fertile" Cervical Mucus Observation
Another body modification that corresponds to the fertile period is the variation in the consistency of the mucus produced at the level of the cervix. In the days preceding ovulation, in fact, these transparent secretions become more fluid, viscous and elastic (similar to egg white). These characteristics are ideal for receiving and facilitating the passage of spermatozoa through the vaginal canal and reaching the egg.
The observation of cervical mucus can also be used as a contraceptive method ( Billings method ); in this regard, it is necessary to abstain from sexual intercourse on fertile days, that is to say when the ovulatory mucus is seen, until the fourth or fifth day after the disappearance of the secretions.
The combination of this method with that of detecting the basal temperature, represents a method of natural contraception ( syntothermal method ).
To learn more: Cervical Mucus - Normal Aspect and Changes »Medical Exams and Home Use Tests
Ovulation Test: how to use it to calculate the Fertile Period
Ovulation tests are similar to those for pregnancy: they detect the presence in the urine of hormones that regulate ovulation (in particular, LH and estradiol), in order to identify fertile days using a visual indicator, such as example of colored lines.
Ovulatory sticks can be purchased in pharmacies and currently represent the most reliable method for self-evaluation of the fertile period .
The test should be repeated for a few days, starting from the date when ovulation is most likely to occur. When a positive outcome is found, it means that the LH has reached a high concentration, so the ovulatory phase is imminent and we find ourselves in the most fertile period of the cycle. Based on this information, if a pregnancy is desired, it is possible to have unprotected intercourse starting from the day the stick is positive .
Ultrasound Monitoring of Ovulation
If establishing the fertile period is complex, the alternative to self-evaluation remains the medical approach . This involves performing a series of ultrasound scans, on alternate days or at intervals set according to the situation, to accurately assess the stage of development and the size of the ovulatory follicles and the appearance of the endometrium.
The examination can be performed trans-abdominal or transvaginal.
Ultrasound monitoring of ovulation is the most precise and safe method to establish the fertile period, however it requires a considerable effort on the part of the patient.
