The value of the method of measuring basal temperature

The female body is a relatively stable system, despite the fact that many different physiological processes occur in it every second, causing blood, urine, body temperature, etc. To fluctuate. Such changes are insignificant, therefore, small deviations from the average value are considered the norm, and moderate and large deviations are considered pathology. For example, the norm in the normal state is considered to be a body temperature of 36.6-36.8 degrees, 36.9 is the borderline value, and 37 in most cases indicates a developing pathological process. But this is not always the case, because many factors affect body temperature: stress, physical activity, the quality of night rest, the presence of chronic pathologies, pregnancy, etc. The basal temperature during pregnancy is above 37 degrees, and this is not considered a pathology. On the contrary, such a change in temperature indicators is a joyful event, testifying to one about the birth of a new life, and to the other - about the right moment for conception. [1]

What is basal body temperature?

The word base in Russian is understood as the basis for something, the indicator from which the countdown of changes, time, processes begins. When it comes to something specific, for example, about temperature, then the base or basal temperature can be considered the one that most accurately reflects the state of the body at the moment.

This is the temperature in a state of complete rest, when it is not yet significantly influenced by factors that can make changes. These factors include:

• physical activity (when a person begins to actively move, metabolic processes accelerate, body temperature rises slightly),
• excited psycho-emotional state (with severe stress and overexcitation, there is an increase in temperature, in some cases even up to 37.5-38 degrees).
• lack of sleep (with a one-time lack of sleep, weakness and a slight decrease in temperature may be noted, and in chronic - an increase in temperature and chills caused by a general overwork of the body, a decrease in its defenses, resistance to infections), etc.

If you measure the body temperature immediately after waking up, without leaving the bed, it will be several tenths of a degree lower than that which we see when a person is actively included in the hectic rhythm of life. Changes in temperature indicators are largely due to the level of physical activity, the state of the psyche and immunity, the degree of fatigue, so during the day the indicators may fluctuate. And this does not allow to assess the true state of the body.

Basal temperature is the one that is noted when a person wakes up even before the start of activity. It is measured in bed, without getting up, taking a thermometer from the bedside table. An important etiological factor is normal rest on the eve of temperature measurement (at least 6-7 hours).

Despite equal measurement conditions, even the base temperature may change in different periods. So, the basal temperature during ovulation and during pregnancy is slightly higher than in other periods of a woman's life. But at the same time, you need to understand that overestimated body temperature can also be the result of inflammatory diseases, the active stage of which is always accompanied by hyperthermia of varying degrees. [2]

Measurement of basal temperature

Since the basal temperature most accurately reflects the processes occurring in the body, it is clear that such a feature of it could not go unnoticed by doctors. The method of its measurement turned out to be useful both for assessing the general state of the body and for diagnosing pathologies of its various structures and systems (immune, endocrine, reproductive, etc.).

The fact that basal temperature can change even in the absence of symptoms of the disease has interested endocrinologists and gynecologists. The fact is that body temperature is able to undergo certain changes under the influence of individual hormones. This explains its increase the day before during ovulation and at conception.

A hyperthermic effect has been seen with progesterone. It is on this property of the hormone that the method of measuring basal temperature during pregnancy and its planning is based, developed in the middle of the last century by the English scientist Marshal, although the effect of female sex hormones on body temperature (estrogen reduces it slightly, and progesterone increases it) has been known since end of the 19th century.

Progesterone is a biologically active substance produced in the body of women and men. But in the latter, it is produced in small quantities and has a lower activity (the effect of it and estrogen is extinguished by the male hormone testosterone), sufficient to maintain the functional norm of the male body.

For women, progesterone is of great value, because it is thanks to him that it is possible to maintain pregnancy and maintain the demographic situation in general. That is why it is called the pregnancy hormone. But this does not mean at all that progesterone is produced only in pregnant women.

The body of a woman is designed in such a way that it is she who responds to procreation. The functioning of the female reproductive system is built on this and is subordinated to this task.

Ideally, the menstrual cycle in women can be divided into 2 phases. In the first, the maturation of one (rarely two or more) follicles occurs, in the second - ovulation and post-ovulation development of the egg. After the maturation of the follicle, a signal is sent to the brain about this, and the pituitary gland releases luteinizing hormone into the blood, which facilitates the release of an egg ready for fertilization from the surrounding follicle. Therefore, the first phase is called follicular, and the second - luteal.

Once during the menstrual cycle (at the beginning of its second phase), the egg is released from the follicle with the formation of a corpus luteum in its place (due to the special substance lutein, which determines the color of the formed gland). The corpus luteum is inherently an organ of internal secretion, which exists for a limited time and is designed to maintain a possible pregnancy in the post-ovulation period.

It is the corpus luteum in the post-ovulation period that is responsible for the synthesis of progesterone, regardless of whether conception occurred during this period or not. During the first week after ovulation, progesterone is secreted in significant amounts in both pregnant and non-pregnant women. But at conception, it continues to stand out in the future, because this is an important condition for maintaining pregnancy. [3]

Where is basal temperature measured?

Progesterone is a special female hormone that has a specific property in the literal sense of the word "heat up the situation." This is not about nervous breakdowns, but about warming up the tissues of the body when the hormone enters the vagina and blood. As a biologically active substance, progesterone has a stimulating effect on the thermoregulatory center in the brain, which corrects the temperature in accordance with the requirements for conception and pregnancy.

Some women believe that it is necessary to measure the basal temperature to determine the time of ovulation when planning pregnancy strictly in the vagina, because it is there that progesterone is synthesized. Perhaps such a measurement is of great value, but not in terms of diagnosing pregnancy, but for detecting gynecological diseases that cause a local increase in the temperature of the genital organs. The basal temperature, which changes during ovulation and pregnancy, is actually the general temperature for the whole body at rest, because we also have blood circulating throughout the body.

It cannot be said that in the place where the hormone is released, i.e. In the internal female organs, the temperature of the tissues changes much more strongly, so it should be measured only in the vagina. Since progesterone, like other hormones, has its effect indirectly, i.e. Through the blood, then it is she who carries this biologically active substance throughout the body, reaching the center of thermoregulation of the brain. The circulatory system in the human body is the same for all organs. In this way, other parts of the body are also heated, so the temperature measured in the oral cavity or rectum during ovulation and after conception after a short period of time will also be higher.

Another thing is that the sex hormone primarily causes an increase in temperature in the area of \u200b\u200bits release (local), signaling the thermoregulation center that it is here that the necessary conditions must be created. But in the future, this causes temperature changes in nearby tissues, and the process spreads further, so fluctuations in basal temperature can be seen even in the oral cavity.

In other words, an indicator of a joyful event or its maximum possibility is an increased temperature in the vagina, rectum or mouth, where it is customary to measure basal temperature. The temperature under the armpits is not considered so indicative and does not provide accurate information about the state of the reproductive system after the release of the egg from the follicle. After all, we are not talking about illness, and the temperature changes slightly. In addition, the external environment affects the skin, so the temperature under the arms is usually lower than that noted on the mucous membranes in places where it is customary to measure it: mouth, rectum, vagina.

The temperature of the internal organs and mucous membranes is always higher than that which is fixed on the surface of the body (skin), although the difference in the norm remains small (only half a degree). And at the same time, it is more stable, because in this case, external influences are minimized. It becomes clear why regular measurements of basal temperature in the oral cavity, vagina or rectum are considered more informative.

There is a reasonable opinion that the most appropriate is the measurement of basal temperature in the rectum. Why is it necessary to measure the temperature rectally, if all the processes associated with the development of the egg and its ovulation occur in the ovaries and vagina of a woman? The authors explain their position by the fact that basal temperature is essentially the temperature of heating the blood of a resting organism, the cyclical changes of which are most noticeable in the rectum adjacent to the female internal reproductive organs.

Thanks to the sex hormone progesterone, depending on the level of its secretion by the endocrine glands, the blood supply to the ovaries and uterus, which have common blood vessels, increases. Temperature fluctuations are immediately transmitted to the rectum, which is in direct contact with the walls of the uterus. The intestine heats up when the temperature of the uterus rises, it turns out that it is among the first to feel changes in basal temperature.

It would seem that the vagina is also connected with the uterus and ovaries by common arteries, but temperature fluctuations are most noticeable in the depths of this structure when in contact with its walls, while the measurement of basal temperature is usually carried out without strongly introducing a thermometer into the vagina. So it turns out that the rectum is the first to recognize and react to changes in temperature in the reproductive organs located outside the reach of the thermometer.

And yet, regardless of the choice of a place for measuring temperature indicators, a woman planning a pregnancy will have to adhere to certain requirements:

• You need to measure the temperature regularly throughout the entire menstrual cycle. This is the only way to notice its small changes during ovulation and conception. If measurements are carried out on a case-by-case basis, then a convenient moment for sexual intercourse with the maximum possibility of conceiving a new life can simply be missed. The fact is that the highest probability of becoming a mother is the day of ovulation. Ovulation occurs in the middle of the menstrual cycle, and this middle is calculated based on the number of days in the cycle, and can shift in different women, especially those whose cycles are not particularly regular. Basal temperature, or rather its measurement, will help determine the day of ovulation most accurately.

But you need to understand that conception can also occur on other days close to the day of ovulation, if a woman matures not one, but two eggs (in both ovaries), which remain viable for 1-2 days and are most favorable to spermatozoa for the first 12 hours. Eggs can mature at the same time or with an interval of up to 7 days, i.e. There will be not one, but two ovulations.

One of the reasons for the later (rarely early) term of conception can also be considered the survivability of spermatozoa (inside the female body, they can remain active for a week, when the likelihood of becoming pregnant remains even if there is no act of love these days). This indicates the errors that are possible if you use not the temperature, but the calendar method for determining the best day for conception and diagnosing pregnancy.

• It is better to support the measurement of basal temperature when  planning  pregnancy  with appropriate records. Using the results of daily measurements, you can easily create a graph by which women with a regular menstrual cycle can calculate the optimal days for conception in the future, even without temperature measurement. Such a schedule will also be useful for diagnosing the processes taking place in a woman’s body: if the basal temperature after ovulation does not gradually decrease for 2 or more weeks, then it’s time to visit a antenatal clinic. It is likely that pregnancy has occurred.

The corpus luteum, which is formed after the release of the egg from the follicle, functions for several months after conception (it is especially active until 6-7 weeks of pregnancy, but with the advent of the placenta begins to lose its role). All this time, it secretes progesterone (the maximum activity of the corpus luteum is noted on the 6-7th day after ovulation) and thereby maintains not only pregnancy, but also an increased body temperature in the expectant mother.

If conception does not occur, the activity of the corpus luteum decreases within a week, and the production of progesterone quickly fades (usually after the 21st day of the cycle), which is accompanied by a decrease in temperature to normal levels in non-pregnant women.

• An important condition for the adequacy and value of measurements is not only their regularity, but also constancy: the same thermometer, approximately the same measurement time (ideally, morning hours), the same place (oral cavity, vagina or rectum) because the temperature varies in different parts of the body.
• It is necessary to measure the basal temperature, starting from the 1st day of the cycle (the first day of menstruation), even before getting out of bed, so it is advisable to have a thermometer on hand after waking up in the morning. Going to the toilet, hygiene procedures, eating should be postponed until later, because any activity of the body affects the temperature indicators (blood circulates more actively and heat exchange occurs between body tissues).

This must be done daily, trying to avoid a significant difference in time (plus or minus half an hour). If for some reason a woman overslept the time of the morning measurement, this should be noted in the graph or diary, because this result will not be accurate enough for dynamic analysis. It is believed that during 1 hour of morning sleep, the basal temperature can rise by 0.1 degrees, i.e. After sleeping an extra couple of hours, you can get an indicator of basal temperature 0.2 degrees higher.

• Only those results are indicative when the body first receives a normal rest for at least 6 hours. At the same time, it is desirable that in the last 3 hours of sleep, rest is not interrupted by trips to the kitchen or to the toilet.

If a woman has to work at night, the temperature should be taken after the body has rested for 3-4 hours (it makes no sense to measure the temperature early in the morning). But it must be said right away that shift work schedules negatively affect hormonal balance and the ability to conceive a child.

During adolescence and young adulthood, night shifts and lack of normal night sleep can lead to impaired pelvic development and problems with conception in the future. The growth of the pelvic bones, which means the normal development of the small pelvis and its organs, is promoted by the pituitary hormone somatotropin, a growth hormone that is produced at night.

During puberty, the production of this hormone is most active, and subsequently decreases markedly. Underdevelopment of the pelvis at puberty in the future is almost impossible to compensate, and as a result, problems with conception, bearing and childbirth.

• For the accuracy of the measurement, the depth of insertion of the thermometer and the time of temperature measurement are important. It is necessary to introduce the device into the oral cavity, rectum and vagina by at least 4 cm, but it also does not make sense to immerse it “with the head”. The measurement time should not be less than 5-7 minutes, when the instrument readings stabilize and will no longer change.
• During menstruation, it is uncomfortable to measure the basal temperature in the vagina, but only those results that correspond to a specific measurement site during the entire cycle are of value. Those. If you measure the temperature in the mouth during menstruation, and after them - in the vagina, there is a certain risk of errors.

Based on these considerations, it can be assumed that when planning a pregnancy, it is better to measure the basal temperature in the rectum, which is located in close proximity to the woman's internal reproductive organs (if there are contraindications to such measurements or other subjective reasons, you can measure the temperature by holding the thermometer in mouth).

During pregnancy and the absence of menstruation, it is best to measure basal temperature in the vagina. This is a fairly effective and safe method of monitoring an ongoing pregnancy, which can signal the risk of its failure, local inflammatory processes, usually associated with a bacterial infection (the temperature in the mouth and rectum may remain unchanged), or the absence of cause for alarm. Such measurements will not bring harm to the fetus, because the thermometer does not need to be inserted deeply (the main thing is to keep track of the sterility of the measuring device so as not to introduce an infection into the genital tract), but it will allow the mother to suspect violations in a timely manner and prevent them by contacting a doctor in time. [4]

Who needs to measure basal temperature and why?

Regular measurement of body temperature at rest gives a clear picture of both the general health of a person and its individual organs and systems, and in particular the reproductive system. From the point of view of gynecology, it is of great value for the control of the condition and functioning of the ovaries. It is on the work of the ovaries that the ability of a woman to procreate primarily depends, because follicles are formed in them with eggs maturing inside - female reproductive cells, which, in agreement with one of the spermatozoa (male reproductive cell), give rise to a new organism.

Often, women turn to a gynecologist whose health does not seem to cause concern, but nevertheless they are unable to conceive a child (conception does not occur at all or a low level of female sex hormones causes miscarriages in the early stages). Usually, after 1-2 years of unsuccessful attempts, such women go for help to a doctor who cannot diagnose and prescribe treatment without knowing the cause of the violations. Often, such causes are hormonal in nature, which will be indicated by the results of measuring basal temperature.

Seeing a doctor and using the temperature method for diagnosing infertility will be useful in case of prolonged unsuccessful attempts to conceive a child (it helps to identify exactly who the man or woman is not capable of conceiving, as well as determine the cause of this in women), regular miscarriages, suspected hormonal disorders in a woman.

In these situations, the doctor himself can offer such a simple and effective diagnostic method, which also helps to identify diseases of the genital (when measuring the temperature in the vagina, inflammatory processes are easily detected) and the endocrine system (taking into account the fact that the sex glands themselves are stimulated by the pituitary gland and adrenal glands during participation of the thyroid gland). In the latter case, it is necessary to consult not only a gynecologist, but also an endocrinologist, because a failure can occur in any link in the endocrine chain, which will affect the synthesis of sex hormones, and in particular progesterone.

It is clear that professional diagnosis of disorders is not limited to measuring basal temperature, drawing up a graph and interpreting it. The doctor is not entitled to make a final diagnosis without laboratory tests and a full examination of the woman, including an analysis of hormones. After all, fluctuations in temperature are not always caused by ovulation and conception, it can also be a symptom of an illness that has not yet declared itself.

Despite the fact that the method of measuring basal temperature refers to the methods of medical diagnostics, its use does not require special equipment and control by a doctor. To measure temperature indicators and draw up a simple graph using them, connecting the dots corresponding to digital temperature indicators, is quite within the power of any woman. Gynecologists themselves often recommend that women use the method when planning pregnancy to determine the optimal day for conception of the female sexual cycle.

But even if the birth of a child is not the most important goal during this period, basal temperature will help identify some abnormalities in the work of the ovaries, which may become an obstacle to pregnancy in the future. For example, the non-maturing of the egg or the absence of ovulation during the normal development of the egg, when it does not leave the ovary and the corpus luteum does not form, which produces progesterone. In such conditions, it is impossible to conceive a child and a woman should consult a doctor in advance to identify the reasons for the non-maturing of the egg and appropriate treatment.

If everything is normal and ovulation occurs, measurements will help:

• avoid unwanted pregnancy, as they will determine the days when it is worth paying special attention to contraception or refraining from intercourse,
• will give certain information about the functioning of the endocrine system and sex glands in particular,
• help to identify hidden pathologies,
• will allow you to determine the time of the beginning of the next menstruation,
• will give an opportunity to determine the possible causes of delayed menstruation, the appearance of unusual discharge (such occur during implantation of the egg 3-7 days after conception, and not only with gynecological diseases).

Expectant mothers, who strictly monitor their health and the course of pregnancy, do not stop measuring even after conception. It is especially important to control changes in basal temperature during the first four weeks of pregnancy, when the chances of miscarriage are especially high. The restructuring of the mother's body makes it more susceptible to any negative factors acting from outside or inside it. Fluctuations in basal temperature in one direction or another from the norm may indicate an increased risk of spontaneous abortion.

Thus, in order to start measuring basal temperature when planning a pregnancy or for preventive purposes, it is not at all necessary to go to a gynecologist for such an appointment. It is much more important to consult a doctor if the graph shows deviations from the norm, which may be evidence of both physiological (pregnancy) and pathological processes. [5]

Pleasant and terrible secrets of basal temperature

When a woman takes measurements of basal temperature for the sake of interest and contraception, she does not care about the absence of pregnancy for a long time and other issues related to procreation, the results of the measurements are unlikely to cause strong emotions in her. When planning a pregnancy, its control or diagnosing infertility, women are more scrupulous about the method and react sharply to any deviations from the generally accepted norm.

If  basal temperature  is measured for the purpose of conceiving and maintaining a child  during pregnancy, then the very fact that it  jumps can be alarming. Sometimes it is groundless, because we have already said that normally the temperature during the menstrual cycle should fluctuate, especially at the phase boundary after ovulation (a large jump in temperature within 0.4 degrees, although usually the difference does not exceed 0.1-0.2 degrees ). It is worse if the schedule remains monotonous throughout all days of the cycle and does not experience noticeable fluctuations. Although the preovulatory drop in temperature is not observed on the graph of about 20% of healthy women, it is clear that the jump in temperature after ovulation will not be so noticeable.

But in some cases, jumps in basal temperature within one of the phases may be evidence of certain pathologies. For example, knowing that in the first phase of the cycle the temperature is usually below 37 degrees, its jumps above this indicator for 2-3 days or a long stay near the normal limit may indicate inflammation of the appendages.

In the second phase of the cycle, the temperature indicators are normally above 37.1 degrees. At the same time, in the first 3 days after ovulation, they grow especially rapidly, then the rate of temperature increase decreases, on the 6th-7th day at conception, a decrease in temperature by 0.2-0.3 degrees is observed (implantation retraction), after which the temperature rises again smoothly, while the corpus luteum is active, i.e. Until the end of the second phase. If, 3 days after ovulation, the temperature continues to rise sharply, one can suspect an inflammatory process in the genital organs, egg pathology, estrogen deficiency, the effect of which on temperature is opposite to that of progesterone.

The basal temperature after ovulation during pregnancy  should remain above 37.1 degrees for at least the first month of pregnancy, but usually some upward deviation from the norm is noted in the second and third months of pregnancy. A temperature in the range of 37.1 -37.3 for 14 or more days after ovulation, in the absence of another menstruation, most likely indicates a joyful event in the life of a woman and her family. A two-week pregnancy is already well defined by tests that will help to ascertain the truth of the desired event.

But even if menstruation has come, this does not mean at all that pregnancy should be ruled out (in some women, menstruation occurs within several months of pregnancy). A shift in the onset of menstruation, unusual discharge, a decrease in the duration of menstrual bleeding may indicate conception, but in such cases, pregnancy is usually considered problematic because of the threat of its disruption in the early stages.

The basal temperature of 36.9 - 37  degrees in the first phase of the cycle  when  planning a  pregnancy  indicates a lack of estrogen in the body. Even if the egg can mature in such conditions and covulate, it is likely to be weak. But usually, with a lack of female hormones, the eggs do not mature and there is no sharp increase in temperature in the second phase of the cycle.

The same temperature in the second phase of the cycle indicates a borderline condition and confirms progesterone deficiency (and sometimes a deficiency of sex hormones in general), regardless of whether conception has occurred or not. In this case, the introduction of hormones from the outside is required, stimulation of hormonal activity, otherwise the chances of conception and the normal course of pregnancy are low.

The basal temperature of 36  degrees  when  planning  pregnancy  may be in the first phase of the menstrual cycle, especially against the background of a general weakening of the body. In the second phase of the cycle, such a low temperature is more likely to be nonsense and is possible only with acute progesterone deficiency. Most likely we are talking about the lack of ovulation, without which conception is impossible.

A strong drop  in basal temperature  in a pregnant woman can be observed  with a missed pregnancy, which requires immediate surgical intervention. The reason for such a disruption of pregnancy can be hormonal disorders, for example, a deficiency of progesterone (which is evidenced by a low level of temperatures), its imbalance with estrogen, dysfunction of not only the ovaries, but also other organs of internal secretion (especially the thyroid gland, pituitary gland and adrenal glands), responsible for maintaining hormonal levels. Usually, the temperature at this temperature does not drop below 36.5 degrees, but these indicators are purely individual. Any decrease in basal temperature during pregnancy below 37 degrees should be regarded as an alarming factor. At 36.8, it is no longer possible to postpone going to the doctor.

With an ectopic pregnancy, the basal temperature  is usually within the normal range, if there are no hormonal disorders. Temperature changes are caused by the production of progesterone, which is released after ovulation - a necessary condition for conception. If they talk about pregnancy, regardless of its location, ovulation occurred in any case, which means that there was a release of a large amount of progesterone into the blood. Thus, the measurement of basal temperature during ectopic pregnancy has no diagnostic value.

Now let's talk about high temperatures. 37.1 - 37.3 degrees are normal indicators of the second phase of the cycle. The states of 37.4 -37.6 degrees are considered borderline. These are generally accepted norms, which may differ depending on the initial temperature in the first phase of the cycle.

If in the second phase of the cycle the temperature exceeds 37.6 degrees, it is highly likely that we can talk about an inflammatory process, although similar results can also be with estrogen deficiency. A basal temperature of 38 degrees during pregnancy  (or in the second phase of the cycle without conception) is noted during infectious and inflammatory processes in the internal genital organs of a woman.

So,  an increase and decrease in basal temperature during pregnancy  can have various  reasons. An excessive increase in temperature is usually associated with inflammatory processes in the reproductive system, and in the first phase of the cycle, it can also be evidence of estrogen deficiency. More unfavorable in terms of conception and pregnancy is considered to be a decrease in temperature, especially in the second phase of the cycle, which is associated with progesterone deficiency, fetal fading, and an increased risk of spontaneous miscarriage in early pregnancy. [6]

Basal temperature during IVF pregnancy

It is not always possible for women to conceive a child naturally. For example, with anatomical defects and obstruction of the fallopian tubes, in vitro fertilization (IVF) often becomes the only way to become the mother of your child.

This method is attractive in that the unborn child receives hereditary information from both parents. It's just that the meeting of the mother's egg and the father's sperm occurs outside of the mother's body. The egg is returned to the mother's body (implanted in the uterus) after conception, i.e. 2-5 days after. After conception, it is considered an embryo.

The problem is that the extraction of mature follicles is carried out even before they break, i.e. Before the formation of the corpus luteum, which produces progesterone. By placing the embryo in the uterus, it is impossible to solve the issue of maintaining pregnancy without the introduction of a hormone that supports it (progesterone) from the outside. Indeed, until the placenta is formed, there will be no one to produce progesterone in sufficient quantities, and adrenal hormones (analogues of hormones secreted by the gonads) are not active enough to maintain pregnancy.

To control the course of IVF pregnancy according to the basal temperature schedule, you need to start measuring it 2-3 months before implantation, with the exception of periods when hormonal stimulation of follicle maturation is carried out before their extraction. This will help doctors determine the normal temperature and hormonal background of a woman, which in the future will make it possible to calculate the required dosage of progesterone.

With natural conception in the first post-ovulation days, the temperature rises to 37.3 degrees. During IVF, in the first days after implantation, temperature indicators can reach 37.5 degrees (the reaction of the body to the introduction of a foreign body is added to the action of progesterone). Ideally, progesterone restrains an aggressive immune response and the temperature is further kept within 37.2-37.4 degrees, as in the natural way of conception. When the embryo implants into the wall of the uterus, a small short-term jump in temperature is possible, but then everything returns to normal.

If the temperature continues to rise, and then declines and falls below 37 degrees, this is most likely evidence of rejection of the embryo as a result of increased activity of the immune system. Although there may be other reasons:

• the temperature sometimes rises or jumps in both directions during an ectopic pregnancy,
• local temperature increase also cause local inflammatory processes,
• hyperthermia is characteristic of common infectious diseases,
• it is also impossible to exclude infectious complications (they are possible at the time of taking the egg or introducing it into the uterus).

Any changes in basal temperature during pregnancy after IVF should be clearly monitored and analyzed during the 1st trimester of pregnancy. After the placentation of the embryo, the placenta takes responsibility for maintaining the pregnancy and it no longer makes sense to monitor the basal temperature, although pregnancy monitoring by specialists should remain regular.

A little about the accuracy and feasibility of the method

 Many experts are skeptical about the method of measuring basal temperature, arguing that its graph itself is not a reliable diagnostic criterion. The thermometer readings can be influenced by various internal and external factors that devalue the graphical method. These factors include: somatic diseases that can cause fever, nighttime and especially morning sexual intercourse, the use of drugs and the use of contraceptives (even one-time), contributing to changes in hormonal levels, stress factors that cause irregular absence of ovulation, etc.

A more informative schedule of basal temperature when planning pregnancy and its onset in the early stages will be if the drawing is accompanied by records of the woman's well-being and situations that can correct the real indicators. If, in the interval between successive temperature measurements, a woman did not have sleep disturbances, unusual discharge, pain not associated with menstruation, nervous shocks, sexual intercourse, stool disorders, no marks need to be made. But it is worth mentioning the medications taken, especially when it comes to steroids, hormone-containing drugs, sexual function stimulants.

By the way, hormonal contraceptives during the menstrual cycle, when the basal temperature is measured, should be abandoned altogether. Indeed, in this case, the thermometer will show temperature changes corresponding to the action of contraceptives, i.e. There is an external influence that changes the course of processes inside the woman's body.

In a separate column, it is worth noting such events as stool disorders (constipation and diarrhea), painful sensations (regardless of their location), the presence of symptoms of the disease, the days of menstruation and the nature of their course, alcohol consumption, sexual contacts, sleep disturbances (frequent awakenings, insufficient duration, weakness after waking up, taking sleeping pills).

Particular attention should be paid to discharge during the menstrual cycle, which is normal in adult women not only during menstruation. For a specialist, information about the nature of the discharge on different days of the cycle will be very valuable. At ovulation, they usually become more abundant, transparent, mucus-like, sometimes streaked with blood. The onset of ovulation may also be indicated by a “filled” and slightly painful chest, increased sexual desire, unusual swelling and slight aching pain in the lower abdomen, sometimes flatulence. All this is also worth mentioning in your notes.

Basal temperature in planning and monitoring pregnancy is an important indicator of the state of the female reproductive system. But it is impossible to rely only on it when making a diagnosis. A normal two-phase cycle is usually understood as a two-phase change in temperature. But at the same time, statistics show that a fifth of healthy women with a two-phase menstrual cycle are diagnosed with a multi-phase change in basal temperature, i.e. Noticeable temperature fluctuations during one phase of the cycle, and not just when they change. Ultrasound and laboratory tests do not confirm any pathologies and obstacles to conception in them, although the schedule looks unusual.

One more moment. In the syndrome of luteinization of the unovulated follicle, ovulation does not occur, but again there is a two-phase change in temperature. True, in this case the rate of temperature increase in the second phase of the cycle is unusually low. This fact is recognized by doctors as a diagnostic criterion. 

Many factors influence changes in basal body temperature. Any active movement, for example, lifting for a thermometer, can reduce the value of the result, not to mention sexual life, medication, lack of sleep, stress, drinking, etc., which in our life are considered ordinary everyday situations. In addition, in order to obtain a reliable result for various disorders, it is necessary to use the method of measuring and comparing basal temperature during not one, but several menstrual cycles. And in any case, this information should be supported by the results of ultrasound and studies on hormones.

Basal temperature during pregnancy and at the stage of its planning cannot be considered the main diagnostic criterion for infertility, miscarriage and many other disorders that prevent a woman from becoming a mother. The results of measurements help the woman and the doctor only to suggest possible hormonal causes of malfunctions of the reproductive system. However, to determine the day of ovulation, dangerous periods when it is worth paying special attention to contraception, daily monitoring of the course of pregnancy in the early stages for timely seeking help if necessary (a kind of safety net), this method is considered quite a worthy alternative.