How is basal temperature measured? Measurement of basal temperature: how, when and where to measure? The essence of the method of basal thermometry

Measurement of basal temperature has become a truly popular means of pregnancy planning.

Why measure basal body temperature

Basal or rectal temperature (BT)- this is the body temperature at rest after at least 3-6 hours of sleep, the temperature is measured in the mouth, rectum or vagina. The temperature measured at this moment is practically not affected by environmental factors. Experience shows that many women perceive the doctor's requirements to measure basal temperature as a formality and basal temperature does not solve anything, but this is far from the case.

The method of measuring basal body temperature was developed in 1953 by the English professor Marshal and refers to research methods based on the biological effect of sex hormones, namely on the hyperthermic (temperature increase) action of progesterone on the thermoregulation center. The measurement of basal body temperature is one of the main tests for the functional diagnosis of ovarian function. Based on the results of measuring BT, a graph is built, an analysis of the graphs of basal temperature is given below.

Measurement of basal temperature and scheduling is recommended in gynecology in the following cases:

If you have been trying to get pregnant for a year without success
If you suspect infertility in yourself or your partner
If your gynecologist suspects you have hormonal disorders

In addition to the above cases, when basal body temperature charting is recommended by a gynecologist, you can measure basal body temperature if:

You want to increase your chances of pregnancy
You are experimenting with the method of planning the sex of the child
You want to observe your body and understand the processes taking place in it (this can help you in communicating with specialists)

Experience shows that many women perceive the doctor's requirements to measure basal temperature as a formality and it does not solve anything.

In fact, by measuring your basal body temperature, you and your doctor can find out:

Does the egg mature and when does it happen (respectively, highlight "dangerous" days for the purpose of protection, or vice versa, the possibility of getting pregnant);
Did ovulation occur after the maturation of the egg?
Determine the quality of your endocrine system
Suspect gynecological problems, such as endometritis
When to expect your next period
Whether pregnancy occurred in case of delayed or unusual menstruation;
Assess how correctly the ovaries secrete hormones in the phases of the menstrual cycle;

A graph of basal temperature, compiled according to all the rules of measurement, can show not only the presence of ovulation in the cycle or its absence, but also indicate diseases of the reproductive and endocrine systems. You must measure your basal temperature for at least 3 cycles so that the information accumulated during this time allows you to make accurate predictions about the expected date of ovulation and the most favorable time for conception, as well as conclusions about hormonal disorders. Only a specialist gynecologist can give an accurate assessment of your basal temperature chart. Charting a basal temperature chart can help a gynecologist determine deviations in the cycle and suggest the absence of ovulation, but at the same time, a diagnosis by a gynecologist only and exclusively based on the type of basal temperature chart without additional tests and examinations most often indicates medical unprofessionalism.

It is necessary to measure the basal temperature, and not the body temperature in the armpit. The general increase in temperature as a result of illness, overheating, physical exertion, eating, stress, naturally affects the basal temperature and makes them unreliable.

Thermometer for measuring basal temperature.

You will need a conventional medical thermometer: mercury or electronic. With a mercury thermometer, the basal temperature is measured for five minutes, while the electronic thermometer must be removed after the signal about the end of the measurement. After he squeaked, the temperature will still rise for a while, because the thermometer fixes the moment when the temperature rises above it very slowly (and do not listen to nonsense about the fact that the thermometer is in bad contact with the muscles of the anus). The thermometer must be prepared in advance, in the evening, by placing it next to the bed. Don't put mercury thermometers under your pillow!

Rules for measuring basal temperature.

It is necessary to measure the basal temperature, if possible, every day, including on the days of menstruation.

You can measure in the mouth, in the vagina or in the rectum. The main thing is that throughout the entire cycle the place of measurement does not change. Armpit temperature measurement is not accurate. With the oral method of measuring basal temperature, you put a thermometer under your tongue and, with your mouth closed, measure for 5 minutes.
For vaginal or rectal measurements, insert the narrow part of the thermometer into the anus or vagina, measuring for 3 minutes. Measurement of temperature in the rectum is the most common.

Take your basal body temperature in the morning, right after waking up and before getting out of bed.

It is necessary to measure the basal temperature at the same time (a difference of half an hour - an hour (maximum one and a half hours) is acceptable). If you decide to sleep in longer on the weekend, make a note of this on your schedule. Keep in mind that every extra hour of sleep raises your basal temperature by about 0.1 degrees.

Uninterrupted sleep before measuring basal temperature in the morning should last at least three hours. Therefore, if you measure the temperature at 8 am, but got up at 7 am to go, for example, to the toilet, it is better to measure BT before that, otherwise, at 8 o'clock familiar to you, it will no longer be informative.

You can use both digital and mercury thermometers to measure. It is important not to change the thermometer during one cycle.
If you use a mercury thermometer, shake it off before you go to sleep. The effort you make to shake off the thermometer just before taking your basal temperature can affect your temperature.

Basal body temperature is measured in the supine position. Do not make unnecessary movements, do not turn around, activity should be minimal. Never get up to take a thermometer! Therefore, it is better to cook it in the evening and put it near the bed in order to be able to reach the thermometer with your hand. Some experts advise taking measurements without even opening your eyes, as daylight can increase the release of certain hormones.

Readings from the thermometer are taken immediately after it is removed.

Basal temperature after measurement is best recorded immediately. Otherwise, you will forget or get confused. Basal temperature every day is approximately the same, differs by tenths of degrees. Relying on your memory, you can get confused in the testimony. If the thermometer readings are between two numbers, record the lower reading.

The graph must indicate the reasons that could lead to an increase in basal temperature (ARI, inflammatory diseases, etc.).

Business trips, moving and flights, sexual intercourse the night before or in the morning can significantly affect the basal temperature.

In diseases accompanied by elevated body temperature, your basal temperature will be uninformative and you can stop measuring for the duration of the illness.

Various medications, such as sleeping pills, sedatives, and hormonal medications, can affect basal body temperature.
Measurement of basal temperature and the simultaneous use of oral (hormonal) contraceptives does not make any sense. The basal temperature depends on the concentration of hormones in the tablets.

After taking a large amount of alcohol, the basal temperature will be uninformative.

When working at night, basal temperature is measured during the day after at least 3-4 hours of sleep.

The basal body temperature (BT) record table should contain the lines:

Day of the month
cycle day
BT
Notes: Abundant or moderate discharge, abnormalities that can affect BBT: general illness, including fever, diarrhea, intercourse in the evening (especially in the morning), drinking alcohol the day before, measuring BBT at an unusual time, going to bed late (for example, went to bed at 3 o'clock, and measured at 6), taking sleeping pills, stress, etc.

The "Notes" column contains all the factors that in one way or another could affect the change in basal temperature.

This form of recording helps both the woman and her doctor to understand the possible causes of infertility, cycle disorders, etc.

Rationale for the basal body temperature method

Basal body temperature during the cycle changes under the influence of hormones.

During the maturation of the egg against the background of a high level of estrogens (the first phase of the menstrual cycle, hypothermic, "low"), the basal temperature is low, on the eve of ovulation it drops to its minimum, and then rises again, reaching a maximum. At this time, ovulation takes place. After ovulation, the high temperature phase begins (the second phase of the menstrual cycle, hyperthermic, "high"), which is caused by low levels of estrogen and high levels of progesterone. Pregnancy under the influence of progesterone also takes place completely in the high temperature phase. The difference between the "low" (hypothermic) and "high" (hyperthermal) phases is 0.4-0.8 °C. Only with accurate measurement of basal body temperature, it is possible to fix the level of "low" temperature in the first half of the menstrual cycle, the transition from "low" to "high" on the day of ovulation, and the temperature level in the second phase of the cycle.

Usually during menstruation, the temperature is kept at 37 ° C. During the maturation of the follicle (the first phase of the cycle), the temperature does not exceed 37°C. Before ovulation itself, it decreases (the result of the action of estrogen), and after it, the basal temperature rises to 37.1 ° C and above (the effect of progesterone). Until the next menstruation, the basal temperature remains elevated and slightly decreases by the first day of menstruation. If the basal temperature in the first phase, relative to the second, is high, then this may indicate a small amount of estrogen in the body and requires correction with drugs containing female sex hormones. On the contrary, if in the second phase, relative to the first, a low basal temperature is observed, then this is an indicator of a low level of progesterone, and drugs are also prescribed here to correct the hormonal background. This should be done only after passing the appropriate tests for hormones and prescribing a doctor.

A persistent two-phase cycle indicates ovulation, which has taken place and the presence of a functionally active corpus luteum (the correct rhythm of the ovaries).
The absence of a rise in temperature in the second phase of the cycle (monotonous curve) or significant temperature fluctuations, both in the first and second half of the cycle with the absence of a stable rise, indicates inoculation (lack of release of the egg from the ovaries).
The delay in the rise and its short duration (hypothermic phase for 2-7, up to 10 days) is observed with a shortening of the luteal phase, insufficient rise (0.2-0.3 ° C) - with insufficient functioning of the corpus luteum.
The thermogenic effect of progesterone leads to an increase in body temperature by at least 0.33 ° C (the effect lasts until the end of the luteal, that is, the second, phase of the menstrual cycle). Progesterone levels peak 8 to 9 days after ovulation, which is approximately the time a fertilized egg implants in the uterine wall.

By making a chart of basal temperature, you can not only determine when you ovulate, but also find out what processes are taking place in your body.

Decoding charts of basal temperature. Examples

If the basal temperature chart is built correctly, taking into account the measurement rules, it can reveal not only the presence or absence of ovulation, but also some diseases.

Break line

The line is drawn over 6 temperature values ​​in the first phase of the cycle, preceding ovulation.

This does not take into account the first 5 days of the cycle, as well as days on which various negative factors could affect the temperature (see temperature measurement rules). This line does not allow any conclusions to be drawn from the graph and is for illustration purposes only.

ovulation line

In order to judge the onset of ovulation, the rules established by the World Health Organization (WHO) are used:

Three temperature values ​​in a row must be above the level of the line drawn over the previous 6 temperature values.
The difference between the midline and the three temperatures must be at least 0.1 degrees on two of the three days and at least 0.2 degrees on one of those days.

If your temperature curve meets these requirements, then an ovulation line will appear on your basal temperature chart 1-2 days after ovulation.

Sometimes it is not possible to determine ovulation according to the WHO method due to the fact that there are high temperatures in the first phase of the cycle. In this case, you can apply the “finger rule” to the basal temperature chart. This rule excludes temperature values ​​that differ from the previous or next temperature by more than 0.2 degrees. Such temperatures should not be taken into account when calculating ovulation, if in general the basal temperature chart is normal.

The most optimal time for conception is the day of ovulation and 2 days before it.

Menstrual cycle length

The total cycle length should normally not be shorter than 21 days and should not exceed 35 days. If your cycles are shorter or longer, then you may have ovarian dysfunction, which is often the cause of infertility and needs to be treated by a gynecologist.

Second phase length

The basal temperature graph is divided into the first and second phases. The separation takes place where the ovulation line (vertical) is affixed. Accordingly, the first phase of the cycle is the segment of the graph before ovulation, and the second phase of the cycle after ovulation.

The length of the second phase of the cycle is normally from 12 to 16 days, most often 14 days. In contrast, the length of the first phase can vary greatly, and these variations are an individual norm. At the same time, in a healthy woman in different cycles, there should not be significant differences in the length of the first phase and the second phase. The total length of the cycle normally changes only due to the length of the first phase.

One of the problems revealed on the graphs and confirmed by subsequent hormonal studies is the insufficiency of the second phase. If you have been measuring your basal temperature for several cycles, following all the measurement rules, and your second phase is shorter than 10 days, this is a reason to consult a gynecologist. Also, if you regularly have sexual intercourse during ovulation, pregnancy does not occur and the length of the second phase is at the lower limit (10 or 11 days), then this may indicate a lack of the second phase.

temperature difference

Normally, the difference in the average temperatures of the first and second phases should be more than 0.4 degrees. If it is lower, then this may indicate hormonal problems. Take a blood test for progesterone and estrogen and consult a gynecologist.

An increase in basal temperature occurs when the level of progesterone in the blood serum exceeds 2.5-4.0 ng / ml (7.6-12.7 nmol / l). However, monophasic basal temperature has been identified in a number of patients with normal progesterone levels in the second phase of the cycle. In addition, monophasic basal temperature is noted at approximately 20% of ovulatory cycles. A simple statement of a two-phase basal temperature does not prove the normal function of the corpus luteum either. Basal temperature also cannot be used to determine the time of ovulation, since a two-phase basal temperature is also observed during luteinization of a non-ovulated follicle. Nevertheless, the duration of the luteal phase in accordance with the data of basal temperature and the low rate of rise in basal temperature after ovulation are accepted by many authors as criteria for diagnosing the syndrome of luteinization of a non-ovulating follicle.

Five main types of temperature curves are described in classic gynecological manuals.

On such graphs, there is an increase in temperature in the second phase of the cycle by at least 0.4 C; noticeable "preovulatory" and "premenstrual" temperature drop. The duration of the temperature increase after ovulation is 12-14 days. Such a curve is typical of a normal biphasic menstrual cycle.

The graph example shows a pre-ovulatory drop on the 12th day of the cycle (the temperature drops significantly two days before ovulation), as well as a premenstrual drop starting from the 26th day of the cycle.

There is a weakly pronounced rise in temperature in the second phase. The temperature difference in the first and second phases is no more than 0.2-0.3 C. Such a curve may indicate estrogen-progesterone deficiency. See chart examples below.

If such schedules are repeated from cycle to cycle, then this may indicate hormonal disruptions that cause infertility.

Basal temperature begins to rise only shortly before menstruation, while there is no "premenstrual" temperature drop. The second phase of the cycle may last less than 10 days. Such a curve is typical for a two-phase menstrual cycle with insufficiency of the second phase. See chart examples below.

Pregnancy in such a cycle is possible, but it is at risk from the very beginning. At this point, a woman still cannot know about the onset of pregnancy, even gynecologists would find it difficult to make a diagnosis at such an early date. With such a schedule, we can talk not about infertility, but about miscarriage. Be sure to contact your gynecologist if you have such a schedule for 3 cycles.

In a cycle without ovulation, the corpus luteum is not formed, which produces the hormone progesterone and affects the increase in basal body temperature. In this case, the temperature rise is not visible on the basal temperature chart and ovulation is not detected. If there is no ovulation line on the chart, in this case we are talking about an anovulatory cycle.

Each woman can have several anovulatory cycles a year - this is normal and does not require medical intervention, but if this situation repeats from cycle to cycle, be sure to consult a gynecologist. Without ovulation - pregnancy is impossible!

A monotonic curve occurs when there is no pronounced rise throughout the cycle. Such a schedule is observed during an anovulatory (ovulation is absent) cycle. See chart examples below.

On average, a woman has one anovulatory cycle per year and there is no cause for concern in this case. But anovulatory schedules that are repeated from cycle to cycle are a very serious reason to contact a gynecologist. Without ovulation, a woman cannot become pregnant and we are talking about female infertility.

estrogen deficiency

Chaotic temperature curve. The graph shows large temperature swings, it does not fit into any of the above types. This type of curve can be observed both in severe estrogen deficiency and depend on random factors. Chart examples below.

A competent gynecologist will definitely require testing for hormones and conduct an ultrasound examination before prescribing medications.

High basal temperature in the first phase

The basal temperature graph is divided into the first and second phases. The separation takes place where the ovulation line (vertical line) is affixed. Accordingly, the first phase of the cycle is the segment of the graph before ovulation, and the second phase of the cycle after ovulation.

Estrogen deficiency

In the first phase of the cycle in the female body, the hormone estrogen dominates. Under the influence of this hormone, the basal temperature before ovulation is kept on average in the range from 36.2 to 36.5 degrees. If the temperature in the first phase rises and stays above this mark, then estrogen deficiency can be assumed. In this case, the average temperature of the first phase rises to 36.5 - 36.8 degrees and is kept at this level. To increase the level of estrogen, gynecologists-endocrinologists will prescribe hormonal drugs.

Estrogen deficiency also leads to an increased temperature in the second phase of the cycle (above 37.1 degrees), while the rise in temperature is slow and takes more than 3 days.

On the example of the graph, the temperature in the first phase is above 37.0 degrees, in the second phase it rises to 37.5, the rise in temperature by 0.2 degrees on the 17th and 18th day of the cycle is insignificant. Fertilization in a cycle with such a schedule is very problematic.

Inflammation of the appendages

Another reason for an increase in temperature in the first phase may be inflammation of the appendages. In this case, the temperature rises only for a few days in the first phase to 37 degrees, and then drops again. In such charts, ovulation calculation is difficult because such a rise "masks" the ovulatory rise.

On the example of the graph, the temperature in the first phase of the cycle is kept at 37.0 degrees, the increase occurs sharply and also falls sharply. A rise in temperature on day 6 of the cycle can be mistaken for an ovulatory rise, but in fact it most likely indicates inflammation. Therefore, it is so important to measure the temperature throughout the cycle in order to exclude such a scenario: the temperature rose due to inflammation, then fell again and then rose due to the onset of ovulation.

endometritis

Normally, the temperature in the first phase should decrease during menstrual bleeding. If your temperature at the end of the cycle drops before the onset of menstruation and rises again to 37.0 degrees with the onset of menstruation (less often on day 2-3 of the cycle), then this may indicate the presence of endometritis.

Characteristically, the temperature drops before menstruation and rises with the beginning of the next cycle. If there is no drop in temperature before the start of menstruation in the first cycle, i.e., the temperature is kept at this level, then pregnancy can be assumed, despite the onset of bleeding. Take a pregnancy test and consult a gynecologist who will conduct an ultrasound for an accurate diagnosis.

If the basal temperature in the first phase rises sharply for one day, then this does not mean anything. Inflammation of the appendages cannot begin and end in one day. Also, a lack of estrogen can only be assumed by evaluating the entire graph, and not a separate temperature in the first phase. In diseases accompanied by high or elevated body temperature, it makes no sense to measure basal temperature, and even more so to judge its nature and analyze the graph.

Low temperature in the second phase of the menstrual cycle

In the second phase of the cycle, the basal temperature should differ significantly (by about 0.4 degrees) from the first phase and be at the level of 37.0 degrees or higher if you measure the temperature rectally. If the temperature difference is less than 0.4 degrees and the average temperature of the second phase does not reach 36.8 degrees, then this may indicate problems.

Insufficiency of the corpus luteum

In the second phase of the cycle, the female body begins to produce the hormone progesterone or the corpus luteum hormone. This hormone is responsible for raising the temperature in the second phase of the cycle and prevents the onset of menstruation. If this hormone is not enough, then the temperature rises slowly and the onset of pregnancy may be at risk.

The temperature in case of corpus luteum insufficiency rises shortly before menstruation, and there is no "premenstrual" fall. This may indicate hormonal deficiency. The diagnosis is based on a blood test for progesterone in the second phase of the cycle. If its values ​​are lowered, then usually the gynecologist prescribes a progesterone substitute: utrogestan or duphaston. These drugs are taken strictly after the onset of ovulation. With the onset of pregnancy, the reception continues until 10-12 weeks. Abrupt withdrawal of progesterone in the second phase during pregnancy can lead to the threat of termination of pregnancy.

Particular attention should be paid to charts with a short second phase. If the second phase is shorter than 10 days, then one can also judge the insufficiency of the second phase.

Situations when the basal temperature remains elevated for more than 14 days occur during pregnancy, the formation of an ovarian corpus luteum cyst, and also in an acute inflammatory process of the pelvic organs.

Estrogen-progesterone deficiency

If, in combination with a low temperature in the second phase, your graph shows a slight rise in temperature (0.2-0.3 C) after ovulation, then such a curve may indicate not only a lack of progesterone, but also a lack of the hormone estrogen.

Hyperprolactinemia

Due to the increase in the level of the pituitary hormone - prolactin, which is responsible for maintaining pregnancy and lactation, the basal temperature graph in this case may resemble the graph of a pregnant woman. Menstruation, as well as during pregnancy, may be absent. An example of a basal temperature chart for hyperprolactinemia

Basal temperature chart for ovulation stimulation

When ovulation is stimulated, in particular with clomiphene (clostilbegyt) using duphaston in the second phase of the mc, the basal temperature graph, as a rule, becomes "normal" - two-phase, with a pronounced phase transition, with a fairly high temperature in the second phase, with characteristic "steps" (the temperature rises 2 times) and a slight sinking. If the temperature schedule during stimulation, on the contrary, is violated and deviates from the normal, this may indicate an incorrect selection of the dose of drugs or an inappropriate stimulation scenario (other medications may be needed). An increase in temperature in the first phase during stimulation with clomiphene also occurs with individual sensitivity to the drug.

Special cases of the basal temperature chart

Low or high temperature in both phases, provided that the temperature difference is at least 0.4 degrees, is not a pathology. This is an individual feature of the body. The measurement method can also affect the temperature values. Typically, with an oral measurement, the basal temperature is 0.2 degrees lower than with a rectal or vaginal measurement.

When to contact a gynecologist?

If you strictly observe the rules for measuring temperature and observe the described problems on your basal temperature graph for at least 2 cycles in a row, contact your doctor for additional examinations. Beware of making diagnoses by a gynecologist only on the basis of charts. What you need to pay attention to:

anovulatory charts
regular cycle delays in case of non-approaching pregnancy
late ovulation and not getting pregnant for several cycles
controversial schedules with indistinct ovulation
high temperature charts throughout the cycle
low temperature curves throughout the cycle
schedules with a short (less than 10 days) second phase
charts with high temperature in the second phase of the cycle for more than 18 days, without the onset of menstruation and a negative pregnancy test
unexplained bleeding or heavy discharge mid-cycle
heavy menstruation lasting more than 5 days
graphs with a temperature difference in the first and second phases of less than 0.4 degrees
cycles shorter than 21 days or longer than 35 days
graphs with well-defined ovulation, regular intercourse during ovulation and no pregnancy for several cycles

Signs of probable infertility according to the basal temperature chart:

The average value of the second phase of the cycle (after the temperature rise) exceeds the average value of the first phase by less than 0.4°C.
In the second phase of the cycle, there are drops in temperature (the temperature drops below 37°C).
The rise in temperature in the middle of the cycle lasts more than 3-4 days.
The second phase is short (less than 8 days).

Definition of pregnancy by basal temperature

The method of determining pregnancy by basal temperature works subject to the presence of ovulation in the cycle, since with some health disorders, the basal temperature can be increased for an arbitrarily long time, and menstruation may be absent. A striking example of such a violation is hyperprolactinemia, due to increased production of the hormone prolactin by the pituitary gland. Prolactin is responsible for maintaining pregnancy and lactation and is normally elevated only during pregnancy and lactation (see Examples of graphs for normal and various disorders).

Fluctuations in basal temperature in different phases of the menstrual cycle are due to different levels of hormones responsible for phases 1 and 2.

During menstruation, the basal temperature is always elevated (about 37.0 and above). In the first phase of the cycle (follicular) before ovulation, the basal temperature is low, up to 37.0 degrees.

Before ovulation, the basal temperature decreases, and immediately after ovulation it rises by 0.4 - 0.5 degrees and remains elevated until the next menstruation.

In women with different lengths of the menstrual cycle, the duration of the follicular phase is different, and the length of the luteal (second) phase of the cycle is approximately the same and does not exceed 12-14 days. Thus, if the basal temperature after the jump (which indicates ovulation) remains elevated for more than 14 days, this clearly indicates the onset of pregnancy.

This method of determining pregnancy works subject to the presence of ovulation in the cycle, since with some health disorders, the basal temperature can be increased for an arbitrarily long time, and menstruation may be absent. A striking example of such a violation is hyperprolactinemia, due to increased production of the hormone prolactin by the pituitary gland. Prolactin is responsible for maintaining pregnancy and lactation and is normally elevated only during pregnancy and lactation.

If a woman is pregnant, then menstruation will not occur and the temperature will remain elevated throughout the pregnancy. A decrease in basal temperature during pregnancy may indicate a lack of hormones that maintain pregnancy and the threat of its termination.

With the onset of pregnancy, in most cases, on the 7th - 10th day after ovulation, implantation occurs - the introduction of a fertilized egg into the endometrium (the inner lining of the uterus). In rare cases, early (before 7 days) or late (after 10 days) implantation is observed. Unfortunately, it is impossible to reliably determine the presence of implantation or its absence either on the basis of the schedule or with the help of ultrasound at a gynecologist's appointment. However, there are several signs that may indicate implantation has taken place. All these signs can be detected on the 7-10th day after ovulation:

It is possible that these days there are small discharges that disappear within 1-2 days. This may be the so-called implantation bleeding. At the time of the introduction of the egg into the inner lining of the uterus, the endometrium is damaged, which leads to minor discharge. But if you have regular discharge in the middle of the cycle, and pregnancy does not occur, then you should contact the gynecology center.

A sharp decrease in temperature to the level of the midline for one day in the second phase, the so-called implantation retraction. This is one of the signs most often observed in charts with confirmed pregnancy. This retraction can occur for two reasons. Firstly, the production of the hormone progesterone, which is responsible for raising the temperature, begins to decline from the middle of the second phase, when pregnancy occurs, its production resumes again, which leads to temperature fluctuations. Secondly, during the onset of pregnancy, the hormone estrogen is released, which in turn lowers the temperature. The combination of these two hormonal shifts leads to the appearance of implantation depression on the graph.

Your chart has become triphasic, which means you are seeing an ovulation-like rise in temperature on the chart during the second phase of your cycle. This rise is again due to increased production of the hormone progesterone after implantation.

On the example of the graph - implantation retraction on the 21st day of the cycle and the presence of the third phase, starting from the 26th day of the cycle.

Early signs of pregnancy such as nausea, tightness in the chest, frequent urination, indigestion, or just feeling pregnant also do not give an accurate answer. You may not be pregnant if you have all of these signs, or you may be pregnant without a single symptom.

All these signs can be a confirmation of the onset of pregnancy, but you should not rely on them, since there are many examples in which the signs were present, but the pregnancy did not occur. Or, conversely, with the onset of pregnancy, there were no signs. The most reliable conclusions can be drawn if there is a clear rise in temperature on your chart, you had intercourse 1-2 days before or during ovulation, and your temperature remains high 14 days after ovulation. In this case, the time has come to take a pregnancy test, which will finally confirm your expectations.

Basal temperature measurement is one of the main fertility tracking methods recognized by the World Health Organization (WHO). for details, see the WHO document "Medical Eligibility Criteria for the Use of Contraceptive Methods" page 117.

When using the basal temperature method to prevent unwanted pregnancy, you need to consider that not only the days of ovulation according to the basal temperature schedule can be dangerous. Therefore, in the period from the beginning of menstruation until the evening of the 3rd day after the rise in basal temperature, which occurs after ovulation, it is better to use additional measures to prevent unwanted pregnancy.

Our regular reader, Natalya Gorshkova, has compiled a form for you to quickly fill out and automatically plot a basal temperature chart, which you can print out and show to your doctor. You can download it from the link: schedule form.

Charts are discussed on the forum

Attention! It is impossible to make any diagnoses only on the basis of basal temperature charts. Diagnosis is made on the basis of additional examinations conducted by a gynecologist.

Measurement of basal body temperature (BT). Rules. Deciphering basal temperature charts

Basal temperature - this is resting body temperature after at least 6 hours of sleep. In different phases of the menstrual cycle, the basal temperature in a woman is constantly changing under the influence of hormonal changes in the female body.

Measurement of basal body temperature BT - a simple functional test that every woman can learn at home. The method is based on the hyperthermic (temperature) effect of progesterone on the thermoregulatory center located in the hypothalamus.

Why you need a basal temperature chart

By drawing up a graph of fluctuations in basal temperature, you can absolutely accurately predict not only the phase of the menstrual cycle at the moment, but also suspect possible deviations from the norm. Let's list what exactly you might need basal body temperature measurement skill in everyday life:

1. If you want to get pregnant and cannot predict when ovulation occurs - a favorable moment for conceiving a child - the release of a mature egg capable of fertilization from the ovarian follicle into the abdominal cavity;
or vice versa - you do not want to get pregnant, thanks to the basal temperature (BT) you can predict “dangerous days”.
2. To determine pregnancy in the early stages with a delay in menstruation.
3. With regular measurement of basal temperature, you can determine the possible reason for the delay in menstruation: pregnancy, lack of ovulation or late ovulation.
4. If your gynecologist suspects that you have hormonal disorders, you or your partner is infertile: if after one year of regular intercourse pregnancy has not occurred, the gynecologist may recommend that you measure basal body temperature (BT) to determine the possible causes of infertility.
5. If you want to plan the gender of your unborn child.

How to measure basal temperature (BT) correctly

As you can see, the correct measurement of basal temperature (BT) helps to answer many important questions. Most women know why they need to measure basal temperature (BT), but few know how to properly conduct a study. Let's try to deal with this issue.

Firstly, you need to immediately understand for yourself that no matter what the obtained indicators of basal temperature (BT) are, this is not a reason for self-diagnosis, and even more so for self-treatment. Only a qualified gynecologist should deal with the interpretation of basal temperature charts.

Secondly, there is no need to draw any fleeting conclusions - basal body temperature (BT) needs at least 3 menstrual cycles to more or less accurately answer questions - when do you ovulate, do you have hormonal disorders, etc. d.

Basic rules for measuring basal temperature (BT)

1. It is necessary to measure basal temperature (BT) from the first day of the menstrual cycle (from the first day of menstruation), otherwise the graph will not reflect the full dynamics of changes.

2. You can measure basal temperature (BT) in the mouth, in the vagina or in the anus, the latter is more preferable. Many gynecologists believe that it is the rectal method that is more reliable and gives fewer errors than all the others. In the mouth, you need to measure the temperature for about 5 minutes, in the vagina and in the rectum for about 3 minutes.
If you measured your basal temperature (BT) in one place, then the location of the thermometer and the duration of the measurement cannot be changed the next time you take a measurement. Today in the mouth, tomorrow in the vagina, and the day after tomorrow in the rectum - such variations are not appropriate and can lead to false diagnosis. Underarm basal temperature (BT) cannot be measured!

3. It is necessary to measure the basal temperature (BT) at the same time, preferably in the morning, immediately after waking up, without getting out of bed.

4. Always use the same thermometer - digital or mercury. If using mercury, be sure to shake well before use.

5. Write down the results immediately, while making notes if there was something that could affect the basal temperature (BT) on this day or the day before: alcohol intake, flight, stress, acute respiratory infections, inflammatory diseases, increased physical activity , sexual intercourse the night before or in the morning, taking medications - sleeping pills, hormones, psychotropic drugs, etc. All these factors can affect the basal temperature and make the study unreliable.

When taking oral contraceptives, measuring BBT does not make any sense!

Thus, in order to make a complete chart of basal body temperature (BT) fluctuations, you will need to label the indicators:
- date of the calendar month;
- day of the menstrual cycle;
- indicators of basal temperature;
- the nature of the discharge from the genital tract on a certain day of the cycle: bloody, mucous, viscous, watery, with yellowness, dry, etc. It is important to note this for the sake of completeness on the chart, as the discharge from the cervical canal becomes more watery during ovulation;
- notes as necessary by a certain day: we enter there all the provoking factors listed above, which may affect the change in BT. For example: I took alcohol the day before, didn’t sleep well or had sex in the morning before the measurement, etc. Notes must be made, even insignificant ones, otherwise the resulting graphs will not correspond to reality.

Generally speaking, your basal temperature records should look like this in a table:

Date Day mts BT Highlights Notes

5 July 13th 36.2 Watery, transparent Drank wine the day before
July 6 14th 36.3 viscous, transparent _________
July 7 15th 36.5 white, viscous _________

Normal basal temperature chart

Before you start drawing up a schedule for basal temperature (BT), you need to know how the basal temperature should normally change under the influence of hormones?

The menstrual cycle in a woman is divided into 2 phases: follicular (hypothermic) and luteal (hyperthermic). In the first phase, the follicle develops, from which the egg is subsequently released. In the same phase, the ovaries intensively produce estrogens. During the follicular phase, BT is below 37 degrees. Then ovulation occurs - in the middle of 2 phases - approximately on the 12-16th day of the menstrual cycle. On the eve of ovulation, BBT drops sharply. Further, during and immediately after ovulation, progesterone is released and BT rises by 0.4-0.6 degrees, which is a reliable sign of ovulation. The second phase - luteal, or it is also called the corpus luteum phase - lasts about 14 days, and if conception does not occur, it ends with menstruation. In the phase of the corpus luteum, very important processes take place - a balance is maintained between low levels of estrogen and high levels of progesterone - thus the corpus luteum prepares the body for a possible pregnancy. In this phase, the basal body temperature (BT) is usually kept at around 37 degrees and above. On the eve of menstruation and in the first days of the cycle, the basal body temperature (BT) again drops by about 0.3 degrees and everything starts anew. That is, normally, every healthy woman should have fluctuations in basal temperature (BT) - if there are no ups and downs, then we can talk about the absence of ovulation, and as a result, infertility.

Consider examples of basal temperature (BT) graphs, as they should be in normal and pathological conditions. The basal temperature (BT) graph that you see below reflects two normal physiological states that a healthy woman can have: 1-lilac curve - basal temperature (BT), which should be during a normal menstrual cycle, ending with menstruation; 2 - light green curve - basal temperature (BT) of a woman with a normal menstrual cycle, we will end in pregnancy. The black line is the ovulation line. The burgundy line is a mark of 37 degrees, it serves for visualization of the graph.

Now let's try to decipher this chart of basal temperature. Please note that a mandatory sign of basal temperature (BT) is normally a two-phase menstrual cycle - that is, both the hypothermic and hyperthermic phases should always be clearly visible on the graph. In the first phase, basal temperature (BT) can range from 36.2 to 36.7 degrees. We observe these fluctuations on this chart from days 1-11 of the cycle. Further, on the 12th day, BBT drops sharply by 0.2 degrees, which is a harbinger of the onset of ovulation. On the 13-14th day, a rise is visible immediately after the fall - ovulation occurs. Further, in the second phase, the basal temperature (BT) continues to rise by 0.4-0.6 degrees compared to the first phase - in this case, up to 37 degrees, and this temperature (marked with a burgundy line) is kept until the end of the menstrual cycle and before the start menstruation falls - on the 25th day of the cycle. On the 28th day of the cycle, the line breaks, which means that the cycle has ended and a new menstrual cycle has begun. But another option is also possible - the light green line, as you can see, does not fall, but continues to grow to 37.1. This means that a woman with a light green line on the basal temperature (BT) chart is most likely pregnant. False-positive results of measuring basal temperature (an increase in basal temperature in the absence of a corpus luteum) can occur with acute and chronic infections, as well as with some changes in the higher parts of the central nervous system.

Important to know when charting your basal temperature!

1. Normally, the menstrual cycle in a healthy woman is from 21 to 35 days, most often 28-30 days, as in the graph. However, for some women, the cycle may be shorter than 21 days, or vice versa, longer than 35. This is a reason to contact a gynecologist. Maybe it's ovarian dysfunction.

2. The graph of basal temperature (BT) should always clearly reflect ovulation, which divides the first and second phases. Always immediately after the preovulatory temperature drop in the middle of the cycle, a woman ovulates - on the chart this is the 14th day, marked with a black line. Therefore, the most optimal time for conception is the day of ovulation and 2 days before it. Using this chart as an example, the most favorable days for conception will be days 12, 13 and 14 of the cycle. And one more nuance: you may not detect a preovulatory decrease in basal temperature (BT) immediately before ovulation, but only see an increase - there is nothing to worry about, most likely ovulation has already begun.

3. The length of the first phase can normally change, lengthen or shorten. But the length of the second phase should not vary normally and is approximately 14 days (plus or minus 1-2 days). If you notice that the second phase is shorter than 10 days, this may be a sign of insufficiency of the second phase and requires a consultation with a gynecologist. In a healthy woman, the duration of the 1st and 2nd phases should normally be approximately the same, for example, 14 + 14 or 15 + 14, or 13 + 14, and so on.

4. Pay attention to the temperature difference between the averages of the first and second phases of the graph. If the difference is less than 0.4 degrees, this may be a sign of hormonal disorders. You need an examination by a gynecologist - take a blood test for progesterone and estrogen. In approximately 20% of cases, such a monophasic graph of BT-basal temperature without a significant temperature difference between the phases is a variant of the norm, and in such patients the hormones are normal.

5. If you have a delay in menstruation, and the hyperthermic (increased) basal temperature of BT lasts more than 18 days, this may indicate a possible pregnancy (light green line on the graph). If menstruation nevertheless came, but the discharge is rather meager and at the same time the basal temperature of BT is still elevated, you urgently need to contact a gynecologist and take a pregnancy test. Most likely - these are signs of a miscarriage that has begun.

6. If the basal temperature of BT in the first phase rose sharply for 1 day, then fell - this is not a sign of concern. This is possible under the influence of provoking factors that affect changes in basal temperature (BT).

Now let's look at examples of BT basal temperature charts for various gynecological pathologies:

The graph is monophasic, i.e. almost without significant temperature fluctuations of the curve. If the rise in basal temperature (BT) in the second phase is mild (0.1-0.3 C) after ovulation, then these are possible signs of a lack of hormones - progesterone and estrogen. You need to take a blood test for these hormones.

If ovulation does not occur and the corpus luteum produced by progesterone does not form, then the basal temperature (BT) curve is monotonous: there are no pronounced jumps or drops - ovulation does not occur, respectively, and a woman with such a basal temperature (BT) schedule cannot become pregnant. An anovulatory cycle is normal in a healthy woman if such a cycle occurs no more than once a year. Accordingly, during pregnancy and lactation, the absence of ovulation is also the norm. If all of the above does not apply to you and this situation is repeated from cycle to cycle, you definitely need to contact a gynecologist. Your doctor will prescribe hormone therapy for you.

The basal temperature of BT rises a few days before the end of the cycle due to hormonal deficiency and does not decrease immediately before menstruation, there is no characteristic preovulatory retraction. The second phase lasts less than 10 days. It is possible to get pregnant with such a schedule of basal temperature (BT), but there is a high probability of miscarriage. We remember that the hormone progesterone is normally produced in the second phase. If the hormone is not synthesized in sufficient quantities, then BT rises very slowly, and the pregnancy may be terminated. With such a schedule of basal temperature (BT), it is necessary to pass an analysis for progesterone in the second phase of the cycle. If progesterone is lowered, then hormonal preparations - gestagens ( Utrozhestan or Duphaston). Pregnant women with low progesterone are prescribed these drugs for up to 12 weeks. With a sharp withdrawal of drugs, a miscarriage may occur.

In the first phase, the basal temperature of BT under the influence of estrogens is kept within 36.2-36.7 C. If the basal temperature of BT in the first phase rises above the indicated mark and if you see sharp jumps and rises on the graph, then most likely there is a lack of estrogens. In the second phase, we see the same picture - ups and downs. On the graph, in the first phase, the basal temperature of BT rises to 36.8 C, i.e. above the norm. In the second phase, there are sharp fluctuations from 36.2 to 37 C (but with a similar pathology they can be higher). Fertility in these patients is drastically reduced. For the purpose of treatment, gynecologists prescribe hormone therapy. Seeing such a graph, there is no need to rush to draw conclusions - such a picture can also be observed in inflammatory gynecological diseases, when everything is in order with estrogens, for example, with inflammation of the appendages. The chart is shown below.

You can see on this graph with sharp ups and downs that, due to the inflammatory process, it is problematic to determine when ovulation occurred, since the basal temperature of BT can increase both during inflammation and during ovulation. On the 9th day of the cycle, we see a rise, which can be mistaken for an ovulatory rise, but this is most likely a sign of an inflammatory process that has begun. This basal temperature (BT) chart proves once again that it is impossible to draw conclusions and make diagnoses based on the basal temperature (BT) chart of one cycle.

We remember that at the beginning of the menstrual cycle, the basal temperature of BT is lowered. If the temperature at the end of the previous cycle decreased, and then rose sharply to 37.0 with the onset of menstruation and does not decrease, as can be seen on the graph, it may be a formidable disease - endometritis and you urgently need treatment from a gynecologist. But if you have a delay in menstruation and at the same time the basal temperature of BBT remains elevated for more than 16 days from the start of the rise, you are probably pregnant.

If you notice that during 3 menstrual cycles you have stable changes on the chart that do not correspond to the norm, you need to consult a specialist.

So, what should alert you when compiling and deciphering basal temperature (BT) charts:

Graphs of basal temperature (BT) with low or high temperature throughout the cycle;
- cycles less than 21 days and more than 35 days. This may be a sign of ovarian dysfunction, clinically manifested by bleeding in the middle of the menstrual cycle. Or there may be a different picture - the cycle is always lengthened, which is expressed in constant delays in menstruation for more than 10 days, while there is no pregnancy;
- if you observe a shortening of the second phase according to the charts;
- if the schedules are anovulatory or the manifestations of ovulation are not clearly expressed on the schedule;
- graphs with high temperature in the second phase for more than 18 days, while there is no pregnancy;
- monophasic graphs: the difference between the first and second phase is less than 0.4 C;
- if the BT schedules are absolutely normal: ovulation occurs, both phases are complete, but pregnancy does not occur within a year with regular unprotected intercourse;
- sharp jumps and rises in BT in both phases of the cycle.

If you follow all the rules for measuring basal temperature, you will discover a lot of new things. Always remember that you do not need to draw any conclusions on the basis of the obtained graphs. This can only be done by a qualified gynecologist, and then only after additional research.

This is the minimum temperature inside the female body. It must be measured after a long rest. The processes occurring in the body are displayed on the temperature measurement. Basal temperature must be measured repeatedly, based on these readings, a graph of fluctuations is drawn up. Thus, it is possible fix the day of ovulation in a girl. Such data are necessary for planning or preventing pregnancy.

How to measure basal temperature to determine pregnancy

Measurements must be done correctly, the accuracy of diagnosing ovulation depends on this. With the help of basal temperature, it is possible to determine the time when pregnancy occurs. Basal temperature should be measured immediately after waking up, without getting out of bed. An important condition for a correct measurement is the non-performing of any movements. You can not raise the body, it is not recommended to stand up.

This is because movement activates the flow of blood, thus increasing the degrees inside the body. BT cannot be measured in the evening, because it is higher at this time. Correct measurement is based on determining the minimum temperature, which is formed due to the work of internal organs, without muscles. That's why temperature measurement is carried out immediately after waking up. The following conditions must be met in order for the temperature to be measured correctly:

In order for the schedule to be correctly drawn up, BBT must be measured at the same time in the morning. Her must be measured from 7 to 9 minutes. The thermometer in the anus should be located at a depth of 4 cm. Measurements are influenced by the following factors:

All of the above situations can affect the correct measurement of BBT. Measurements must be taken while lying down. If the measurement takes place in a vertical position, then this causes blood flow to the pelvic organs, due to this, the internal temperature in the body rises. And then the thermometer readings are unreliable.

How to measure basal temperature

In order for BBT to be measured correctly, the thermometer must be inserted into the anus, vagina or mouth. In 1953, a special technique for measuring basal temperature was developed. Professor of Medicine Marshall offers to measure BBT in the rectum through the anus.

It is this method that measures the temperature in the baby. Measuring the temperature in the anus or vagina in a woman allows you to find out the results of fluctuations in tenths of a degree. It is the tenths that show the jump in the indicator during ovulation.

How to use the obtained indicators

Measurement of BBT is necessary to diagnose ovulation of the egg. - this is the release of the egg from the follicle, which occurs after maturation. The egg enters the tube and moves further to the uterus. Such changes are marked by an increase of a tenth of a degree. Before ovulation, the internal temperature decreases slightly, and then rises sharply.

When the egg is released, conception becomes possible during this period. If the measurement is performed daily, then you can set the date of ovulation. This can allow a woman to get rid of an unwanted pregnancy. Or these indicators can be used to determine the term of conception.

How to plot your basal body temperature correctly

The data is entered into a table, and a graph is built on the basis of this. When recording results, additional factors must be taken into account. Diagnostic accuracy is affected by:

1. Cold.
2. Headache.
3. Infection.

The graph is a broken line. At the very beginning of the cycle, the temperature measurement indicator is in the region of 36.7 - 37 degrees. If BT fluctuates between 0.1 - 0.2 degrees, then this is acceptable. After the arrival of menstruation in a woman, BT drops to the lowest level, which is 36.7 - 36.9 degrees.

This BT is needed for egg maturation. The ripening period is 14 days, so the graph readings will be from 36.8 C - fluctuations of 0.1 or 0.2 degrees can occur from this indicator. In the middle of the cycle before ovulation in 24 hours, the degree drops by 0.2 or 0.3 C, after which a sharp rise up by 0.4 - 0.8 C is noticed. As a result, the basal temperature will be 37.1 C or higher.

Temperature measurement during ovulation

At the time of ovulation, there is a slight decrease in BBT before the jump to 37.1 degrees. During this period, the possibility of conception is 35%. If a woman is not planning a pregnancy, then it is necessary to limit sexual contacts. Other indicators of the schedule will depend on whether the woman became pregnant or her body is preparing for menstruation.

1. If a woman is pregnant, then BT shows the highest level. Progesterone is formed in the body, it maintains the highest value of basal temperature.
2. If the pregnancy does not take place, then the hormonal background returns to its normal level, and then the temperature drops. Such a jump occurs a week before menstruation. At this time, BT decreases by 0.5 - 0.7 degrees.
3. These are the most likely parameters for measuring temperature during ovulation for a healthy woman.

If a failure occurs in the female body, then the schedule is a little off, the temperature jump is not so noticeable. Then BBT measurements are not effective. It must be borne in mind that pregnancy can occur even if there is no temperature jump.

How to diagnose pathologies by basal temperature

It is necessary to make a full cycle of measurements of jumps in BBT within 30 days, due to these data it is possible to diagnose infertility or other disorders of the functioning of the genital organs. Often infertility occurs due to lack of ovulation. Measuring BBT helps a woman find out if she has an egg release or not, and on which days of the cycle it is better to get pregnant.

BBT measurements help determine the presence of inflammation in other organs. This method of determining other diseases is completely suitable for use at home, it is available to all women. With the help of temperature measurement, hidden pathologies can be detected.

What days can conception occur

If measurements are taken over several months, this will help predict ovulation with great accuracy. According to the compiled parameters, you can determine when you can conceive a child. And you can also determine the period when it is impossible to get pregnant. Such information is used by a woman to prevent pregnancy or to conceive a child.

woman measuring BBT is called biological contraception. This is the safest way to control birth. Conception, most likely, within 2 days after the release of the egg from the follicle. And also three or four days before ovulation. During this period, the egg cannot be fertilized. Spermatozoa keep their activity for two days. When spermatozoa first enter the vagina, and then enter the uterus, they remain in it for several more days.

The egg is fertilized immediately after leaving the follicle. Therefore, 3 or 4 days before ovulation are added to the days of possible conception. The period of ovulation and the days before it are considered the most effective. If a woman does not plan pregnancy, then it is necessary to refrain from sex or protect herself with contraceptives. If a child is planned, then it is necessary to have sex the day before ovulation or on the day the egg is released.

1. It is necessary to correctly determine the release of the egg, for this it is necessary to make a correct measurement of temperature measurements in the vagina.
2. The day of ovulation is a slight decrease in the degree, and on the following day, the BBT indicator increases.
3. It is these two days that are considered the most dangerous for opponents of pregnancy or favorable for those who are expecting a child.
4. The life span of an egg after an ovary is 24 hours. If the egg is not fertilized, it is destroyed within 24 hours.
5. Then the probability of pregnancy two days after ovulation is impossible.

Many studies have been done by experts, during which it turned out that Y-spermatozoa have the highest activity. They are responsible for the conception of the boy. Such spermatozoa move much faster and are the first to fertilize the egg. But X-spermatozoa, which are responsible for the conception of a girl, are more hardy.

Thus, if sexual intercourse occurred a few days before ovulation, then the spermatozoa that are responsible for conceiving a girl will live to meet the egg. Using such data, it is possible with a high degree of probability to plan the sex of the baby. All of the above methods for the period of impossible and possible conception are not suitable for all women. This protection system works only in case that, if a woman has stable periods. For all other women, this method is invalid.

Indicators of basal temperature during pregnancy

A change in the characteristics of BT is a consequence of hormonal changes. The most vital currents in a girl's body occur due to hormonal transformations. That is why the onset of pregnancy is formed by a change in BT. If the woman is pregnant, then her BT is at a high level, above 37.3 degrees.

The presence of high BBT is formed by the hormone progesterone. The woman's body intensively produces it in the first 3.5 months of gestation. That is why the temperature indicator at this time is too high. After that, the level of the hormone decreases, so there is a decrease in BT. After 20 weeks of pregnancy, it makes no sense to measure the temperature difference.

By changing the jump in temperature, one can judge the onset of pregnancy before the delay in menstruation. But this sign is ambiguous. A high temperature may be due to physical exertion, inflammatory diseases or medication. Therefore, in order to accurately determine the onset of pregnancy, you need to use a test. A high BBT is used as an indirect method for determining pregnancy.

How to correctly measure basal temperature to establish pregnancy

To do this, two main requirements must be met:

1. BBT should be measured by a woman when she is in a horizontal position.
2. You must not get out of bed before the measurement.
3. Before going to bed, the thermometer should be placed next to the bed.
4. It must be placed at that distance so that it can be easily reached by hand.
5. In this case, the body cannot be turned over.

The temperature reading level must be measured same time in the morning. The measurement difference should not be more than 15 minutes. During the day, the temperature cannot be measured, because the daily measurement will not show the necessary changes inside the body. If the temperature is measured daily in the morning, then it will show a reflection of the reality of the state of hormones.

If a woman knows what her basal temperature is before menstruation, then she will be able to diagnose early pregnancy. If there was sex without contraceptives, then you can find out about the presence of pregnancy before the delay in menstruation. This is what BT measurements are for. If the level of basal temperature does not decrease, then the woman is pregnant.

Control of basal body temperature helps a woman to detect changes in the body in a timely manner. It is this data that can show minor changes that cannot be seen externally. Many people are interested in knowing what basal temperature should be during the day and in the evening.

Under the basal temperature is understood the smallest mark recorded by the thermometer when measured after at least three to four hours of rest. Sleep ideal. It is conditionally called basal, since it is impossible to fix a true basal temperature at home. But, at the same time, the method is good enough to fix the temperature, which is determined not by the activity of a person, but by the basic (basal) function of the internal organs.

For example, to monitor the menstrual cycle and calculate the day of ovulation and the best period for conception.

Changes

Body temperature changes throughout the day depending on the activity of the person. Both physical and psycho-emotional. Therefore, the temperature measured during the day or in the evening cannot be considered basal. It will depend on external factors.

So, for example, as a result of daily activities, the evening temperature in the anus can normally reach values ​​of 37.5 - 37.7ºС in any phase of the menstrual cycle.

Influence on body temperature and activities such as eating (digestion), sexual intercourse, training, experienced stress or joy, taking medications, certain vitamins and dietary supplements. Of course, taking hormonal drugs will distort the values ​​​​of basal temperature.

Basal temperature - this is resting body temperature after at least 6 hours of sleep. In different phases of the menstrual cycle, the basal temperature in a woman is constantly changing under the influence of hormonal changes in the female body.

Measurement of basal body temperature BT - a simple functional test that every woman can learn at home. The method is based on the hyperthermic (temperature) effect of progesterone on the thermoregulatory center located in the hypothalamus.

Why you need a basal temperature chart

By drawing up a graph of fluctuations in basal temperature, you can absolutely accurately predict not only the phase of the menstrual cycle at the moment, but also suspect possible deviations from the norm. Let's list what exactly you might need basal body temperature measurement skill in everyday life:

1. If you want to get pregnant and cannot predict when ovulation occurs - a favorable moment for conceiving a child - the release of a mature egg capable of fertilization from the ovarian follicle into the abdominal cavity;
or vice versa - you do not want to get pregnant, thanks to the basal temperature (BT) you can predict “dangerous days”.
2. To determine pregnancy in the early stages with a delay in menstruation.
3. With regular measurement of basal temperature, you can determine the possible reason for the delay in menstruation: pregnancy, lack of ovulation or late ovulation.
4. If your gynecologist suspects that you have hormonal disorders, you or your partner is infertile: if after one year of regular intercourse pregnancy has not occurred, the gynecologist may recommend that you measure basal body temperature (BT) to determine the possible causes of infertility.

5. If you want to plan the gender of your unborn child.

How to measure basal temperature (BT) correctly

As you can see, the correct measurement of basal temperature (BT) helps to answer many important questions. Most women know why they need to measure basal temperature (BT), but few know how to properly conduct a study. Let's try to deal with this issue.

Firstly, you need to immediately understand for yourself that no matter what the obtained indicators of basal temperature (BT) are, this is not a reason for self-diagnosis, and even more so for self-treatment. Only a qualified gynecologist should deal with the interpretation of basal temperature charts.

Secondly, there is no need to draw any fleeting conclusions - basal body temperature (BT) needs at least 3 menstrual cycles to more or less accurately answer questions - when do you ovulate, do you have hormonal disorders, etc. d.

Basic rules for measuring basal temperature (BT)

1. It is necessary to measure basal temperature (BT) from the first day of the menstrual cycle (from the first day of menstruation), otherwise the graph will not reflect the full dynamics of changes.

2. You can measure basal temperature (BT) in the mouth, in the vagina or in the anus, the latter is more preferable. Many gynecologists believe that it is the rectal method that is more reliable and gives fewer errors than all the others. In the mouth, you need to measure the temperature for about 5 minutes, in the vagina and in the rectum for about 3 minutes.
If you measured your basal temperature (BT) in one place, then the location of the thermometer and the duration of the measurement cannot be changed the next time you take a measurement. Today in the mouth, tomorrow in the vagina, and the day after tomorrow in the rectum - such variations are not appropriate and can lead to false diagnosis. Underarm basal temperature (BT) cannot be measured!

3. It is necessary to measure the basal temperature (BT) at the same time, preferably in the morning, immediately after waking up, without getting out of bed.

4. Always use the same thermometer - digital or mercury. If using mercury, be sure to shake well before use.

5. Write down the results immediately, while making notes if there was something that could affect the basal temperature (BT) on this day or the day before: alcohol intake, flight, stress, acute respiratory infections, inflammatory diseases, increased physical activity , sexual intercourse the night before or in the morning, taking medications - sleeping pills, hormones, psychotropic drugs, etc. All these factors can affect the basal temperature and make the study unreliable.

When taking oral contraceptives, measuring BBT does not make any sense!

Thus, in order to make a complete chart of basal body temperature (BT) fluctuations, you will need to label the indicators:
- date of the calendar month;
- day of the menstrual cycle;
- indicators of basal temperature;
- the nature of the discharge from the genital tract on a certain day of the cycle: bloody, mucous, viscous, watery, with yellowness, dry, etc. It is important to note this for the sake of completeness on the chart, as the discharge from the cervical canal becomes more watery during ovulation;
- notes as necessary by a certain day: we enter there all the provoking factors listed above, which may affect the change in BT. For example: I took alcohol the day before, didn’t sleep well or had sex in the morning before the measurement, etc. Notes must be made, even insignificant ones, otherwise the resulting graphs will not correspond to reality.

Generally speaking, your basal temperature records should look like this in a table:

Date Day mts BT Highlights Notes

5 July 13th 36.2 Watery, transparent Drank wine the day before
July 6 14th 36.3 viscous, transparent _________
July 7 15th 36.5 white, viscous _________

Normal basal temperature chart

Before you start drawing up a schedule for basal temperature (BT), you need to know how the basal temperature should normally change under the influence of hormones?

The menstrual cycle in a woman is divided into 2 phases: follicular (hypothermic) and luteal (hyperthermic). In the first phase, the follicle develops, from which the egg is subsequently released. In the same phase, the ovaries intensively produce estrogens. During the follicular phase, BT is below 37 degrees. Then ovulation occurs - in the middle of 2 phases - approximately on the 12-16th day of the menstrual cycle. On the eve of ovulation, BBT drops sharply. Further, during and immediately after ovulation, progesterone is released and BT rises by 0.4-0.6 degrees, which is a reliable sign of ovulation. The second phase - luteal, or it is also called the corpus luteum phase - lasts about 14 days, and if conception does not occur, it ends with menstruation. In the phase of the corpus luteum, very important processes take place - a balance is maintained between low levels of estrogen and high levels of progesterone - thus the corpus luteum prepares the body for a possible pregnancy. In this phase, the basal body temperature (BT) is usually kept at around 37 degrees and above. On the eve of menstruation and in the first days of the cycle, the basal body temperature (BT) again drops by about 0.3 degrees and everything starts anew. That is, normally, every healthy woman should have fluctuations in basal temperature (BT) - if there are no ups and downs, then we can talk about the absence of ovulation, and as a result, infertility.

Consider examples of basal temperature (BT) graphs, as they should be in normal and pathological conditions. The basal temperature (BT) graph that you see below reflects two normal physiological states that a healthy woman can have: 1-lilac curve - basal temperature (BT), which should be during a normal menstrual cycle, ending with menstruation; 2 - light green curve - basal temperature (BT) of a woman with a normal menstrual cycle, we will end in pregnancy. The black line is the ovulation line. The burgundy line is a mark of 37 degrees, it serves for visualization of the graph.

Now let's try to decipher this chart of basal temperature. Please note that a mandatory sign of basal temperature (BT) is normally a two-phase menstrual cycle - that is, both the hypothermic and hyperthermic phases should always be clearly visible on the graph. In the first phase, basal temperature (BT) can range from 36.2 to 36.7 degrees. We observe these fluctuations on this chart from days 1-11 of the cycle. Further, on the 12th day, BBT drops sharply by 0.2 degrees, which is a harbinger of the onset of ovulation. On the 13-14th day, a rise is visible immediately after the fall - ovulation occurs. Further, in the second phase, the basal temperature (BT) continues to rise by 0.4-0.6 degrees compared to the first phase - in this case, up to 37 degrees, and this temperature (marked with a burgundy line) is kept until the end of the menstrual cycle and before the start menstruation falls - on the 25th day of the cycle. On the 28th day of the cycle, the line breaks, which means that the cycle has ended and a new menstrual cycle has begun. But another option is also possible - the light green line, as you can see, does not fall, but continues to grow to 37.1. This means that a woman with a light green line on the basal temperature (BT) chart is most likely pregnant. False-positive results of measuring basal temperature (an increase in basal temperature in the absence of a corpus luteum) can occur with acute and chronic infections, as well as with some changes in the higher parts of the central nervous system.

Important to know when charting your basal temperature!

1. Normally, the menstrual cycle in a healthy woman is from 21 to 35 days, most often 28-30 days, as in the graph. However, for some women, the cycle may be shorter than 21 days, or vice versa, longer than 35. This is a reason to contact a gynecologist. Maybe it's ovarian dysfunction.

2. The graph of basal temperature (BT) should always clearly reflect ovulation, which divides the first and second phases. Always immediately after the preovulatory temperature drop in the middle of the cycle, a woman ovulates - on the chart this is the 14th day, marked with a black line. Therefore, the most optimal time for conception is the day of ovulation and 2 days before it. Using this chart as an example, the most favorable days for conception will be days 12, 13 and 14 of the cycle. And one more nuance: you may not detect a preovulatory decrease in basal temperature (BT) immediately before ovulation, but only see an increase - there is nothing to worry about, most likely ovulation has already begun.

3. The length of the first phase can normally change, lengthen or shorten. But the length of the second phase should not vary normally and is approximately 14 days (plus or minus 1-2 days). If you notice that the second phase is shorter than 10 days, this may be a sign of insufficiency of the second phase and requires a consultation with a gynecologist. In a healthy woman, the duration of the 1st and 2nd phases should normally be approximately the same, for example, 14 + 14 or 15 + 14, or 13 + 14, and so on.

4. Pay attention to the temperature difference between the averages of the first and second phases of the graph. If the difference is less than 0.4 degrees, this may be a sign of hormonal disorders. You need to be examined by a gynecologist - take a blood test for progesterone and estrogen. In approximately 20% of cases, such a monophasic graph of BT-basal temperature without a significant temperature difference between the phases is a variant of the norm, and in such patients the hormones are normal.

5. If you have a delay in menstruation, and the hyperthermic (increased) basal temperature of BT lasts more than 18 days, this may indicate a possible pregnancy (light green line on the graph). If menstruation nevertheless came, but the discharge is rather meager and at the same time the basal temperature of BT is still elevated, you urgently need to contact a gynecologist and take a pregnancy test. Most likely - these are signs of a miscarriage that has begun.

6. If the basal temperature of BT in the first phase rose sharply for 1 day, then fell - this is not a sign of concern. This is possible under the influence of provoking factors that affect changes in basal temperature (BT).

Now let's look at examples of BT basal temperature charts for various gynecological pathologies:

The graph is monophasic, i.e. almost without significant temperature fluctuations of the curve. If the rise in basal temperature (BT) in the second phase is mild (0.1-0.3 C) after ovulation, then these are possible signs of a lack of hormones - progesterone and estrogen. You need to take a blood test for these hormones.

If ovulation does not occur and the corpus luteum produced by progesterone does not form, then the basal temperature (BT) curve is monotonous: there are no pronounced jumps or drops - ovulation does not occur, respectively, and a woman with such a basal temperature (BT) schedule cannot become pregnant. An anovulatory cycle is normal in a healthy woman if such a cycle occurs no more than once a year. Accordingly, during pregnancy and lactation, the absence of ovulation is also the norm. If all of the above does not apply to you and this situation is repeated from cycle to cycle, you definitely need to contact a gynecologist. Your doctor will prescribe hormone therapy for you.

The basal temperature of BT rises a few days before the end of the cycle due to hormonal deficiency and does not decrease immediately before menstruation, there is no characteristic preovulatory retraction. The second phase lasts less than 10 days. It is possible to get pregnant with such a schedule of basal temperature (BT), but there is a high probability of miscarriage. We remember that the hormone progesterone is normally produced in the second phase. If the hormone is not synthesized in sufficient quantities, then BT rises very slowly, and the pregnancy may be terminated. With such a schedule of basal temperature (BT), it is necessary to pass an analysis for progesterone in the second phase of the cycle. If progesterone is lowered, then hormonal preparations - gestagens (Utrozhestan or Duphaston) are necessarily prescribed in the second phase. Pregnant women with low progesterone are prescribed these drugs for up to 12 weeks. With a sharp withdrawal of drugs, a miscarriage may occur.

In the first phase, the basal temperature of BT under the influence of estrogens is kept within 36.2-36.7 C. If the basal temperature of BT in the first phase rises above the indicated mark and if you see sharp jumps and rises on the graph, then most likely there is a lack of estrogens. In the second phase, we see the same picture - ups and downs. On the graph, in the first phase, the basal temperature of BT rises to 36.8 C, i.e. above the norm. In the second phase, there are sharp fluctuations from 36.2 to 37 C (but with a similar pathology they can be higher). Fertility in these patients is drastically reduced. For the purpose of treatment, gynecologists prescribe hormone therapy. Seeing such a graph, there is no need to rush to draw conclusions - such a picture can also be observed in inflammatory gynecological diseases, when everything is in order with estrogens, for example, with inflammation of the appendages. The chart is shown below.

You can see on this graph with sharp ups and downs that, due to the inflammatory process, it is problematic to determine when ovulation occurred, since the basal temperature of BT can increase both during inflammation and during ovulation. On the 9th day of the cycle, we see a rise, which can be mistaken for an ovulatory rise, but this is most likely a sign of an inflammatory process that has begun. This basal temperature (BT) chart proves once again that it is impossible to draw conclusions and make diagnoses based on the basal temperature (BT) chart of one cycle.

We remember that at the beginning of the menstrual cycle, the basal temperature of BT is lowered. If the temperature at the end of the previous cycle decreased, and then rose sharply to 37.0 with the onset of menstruation and does not decrease, as can be seen on the graph, it may be a formidable disease - endometritis and you urgently need treatment from a gynecologist. But if you have a delay in menstruation and at the same time the basal temperature of BBT remains elevated for more than 16 days from the start of the rise, you are probably pregnant.

If you notice that during 3 menstrual cycles you have stable changes on the chart that do not correspond to the norm, you need to consult a specialist.

So, what should alert you when compiling and deciphering basal temperature (BT) charts:

Graphs of basal temperature (BT) with low or high temperature throughout the cycle;
- cycles less than 21 days and more than 35 days. This may be a sign of ovarian dysfunction, clinically manifested by bleeding in the middle of the menstrual cycle. Or there may be a different picture - the cycle is always lengthened, which is expressed in constant delays in menstruation for more than 10 days, while there is no pregnancy;
- if you observe a shortening of the second phase according to the charts;
- if the schedules are anovulatory or the manifestations of ovulation are not clearly expressed on the schedule;
- graphs with high temperature in the second phase for more than 18 days, while there is no pregnancy;
- monophasic graphs: the difference between the first and second phase is less than 0.4 C;
- if the BT schedules are absolutely normal: ovulation occurs, both phases are complete, but pregnancy does not occur within a year with regular unprotected intercourse;
- sharp jumps and rises in BT in both phases of the cycle.

If you follow all the rules for measuring basal temperature, you will discover a lot of new things. Always remember that you do not need to draw any conclusions on the basis of the obtained graphs. This can only be done by a qualified gynecologist, and then only after additional research.

Obstetrician-gynecologist, Ph.D. Christina Frambos.