Basal temperature charts with examples and explanation. Basal temperature during pregnancy and its planning, temperature chart

Measurement basal temperature it has truly become folk remedy pregnancy planning.

Why measure basal 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 factors external environment. Experience shows that many women perceive the doctor’s demands 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 Marshall and refers to research techniques that are based on the biological effect of sex hormones, namely on the hyperthermic (increase in temperature) action of progesterone on the thermoregulation center. Measuring basal body temperature is one of the main tests functional diagnostics work of the ovaries. Based on the results of measuring BT, a graph is constructed; an analysis of basal temperature graphs is given below.

Measuring basal temperature and charting is recommended in gynecology in the following cases:

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

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

• Do you want to increase your chances of pregnancy?
• You are experimenting with methods of planning the gender of your child
• You want to observe your body and understand the processes taking place in it (this can help you communicate with specialists)

Experience shows that many women perceive the doctor’s demands 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 this happen (accordingly, highlight “dangerous” days for the purpose of protection or, conversely, the possibility of getting pregnant);
• Did ovulation occur after the egg matured?
• Determine the quality of your work endocrine system
• Suspect gynecological problems, such as endometritis
• When to expect your next menstruation
• Whether pregnancy occurred due to delay or unusual menstruation;
• Assess how correctly the ovaries secrete hormones in phases menstrual cycle;

A graph of basal temperature, drawn up according to all measurement rules, can show not only the presence of ovulation in a 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 of conception, as well as conclusions about hormonal disorders. Only a gynecologist can give an accurate assessment of your basal temperature chart. Drawing up a basal temperature chart can help a gynecologist determine deviations in the cycle and suggest the absence of ovulation, but at the same time, the gynecologist makes a diagnosis only and exclusively by looking at the basal temperature chart without additional tests and examinations most often indicate medical unprofessionalism.

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

Thermometer for measuring basal temperature.

You will need a regular medical thermometer: mercury or electronic. Using a mercury thermometer, measure your basal temperature for five minutes. electronic thermometer it must be removed after the signal about the end of the measurement. After it squeaks, the temperature will continue to rise for some time, since the thermometer records the moment when the temperature rises above very slowly (and don’t listen to the nonsense about the thermometer not being in good contact with the muscles of the anus). The thermometer must be prepared in advance, in the evening, by placing it next to the bed. Do not place mercury thermometers under your pillow!

Rules for measuring basal temperature.
1. You should measure your basal temperature every day if possible, including on your period.

2. You can measure in the mouth, vagina or rectum. The main thing is that the measurement location does not change throughout the entire cycle. Measuring armpit temperature does not provide accurate results. With the oral method of measuring basal temperature, you place the thermometer under your tongue and measure for 5 minutes with your mouth closed.
When using the vaginal or rectal method of measurement, insert the narrow part of the thermometer into the anus or vagina, the measurement duration is 3 minutes. Measuring temperature in the rectum is the most common.

3. Measure your basal temperature in the morning, immediately after waking up and before getting out of bed.

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

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

6. You can use either a digital or a mercury thermometer to measure. It is important not to change the thermometer during one cycle.
If you use mercury thermometer, then shake it off before going to sleep. The effort you use to shake off the thermometer immediately before measuring your basal temperature can affect your temperature.

7. Basal temperature is measured while lying still. Do not make unnecessary movements, do not turn, activity should be minimal. Do not under any circumstances get up to take a thermometer! Therefore, it is better to prepare it in the evening and place it near the bed so that you can reach the thermometer with your hand. Some experts advise taking the measurement without even opening your eyes, since daylight can increase the release of certain hormones.

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

9. After measurement, it is best to immediately write down your basal temperature. Otherwise you will forget or get confused. The basal temperature is approximately the same every day, differing by tenths of degrees. Relying on your memory, you can get confused in the readings. If the thermometer readings are between two numbers, record the lower reading.

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

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

12. For diseases accompanied elevated temperature body, your basal temperature will be uninformative and you can stop taking measurements for the duration of your illness.

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

14. After reception large quantity alcohol, the basal temperature will be uninformative.

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

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

Day of the month
Cycle day
BT
Notes: Heavy or moderate discharge, deviations that can affect BT: general disease, including with an increase in temperature, diarrhea, intercourse in the evening (and even more so in the morning), drinking alcohol the day before, measuring BT at an unusual time, going to bed late (for example, I went to bed at 3 o’clock and measured it at 6), taking sleeping pills, stress, etc.

All factors that could in one way or another affect the change in basal temperature are entered in the “Notes” column.

This form of recording is very helpful for both the woman and her doctor to understand possible reasons infertility, cycle disorders, etc.

Rationale for the basal body temperature method

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

During the maturation of the egg against the background of a high level of estrogen (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 hour, ovulation occurs. After ovulation, a phase of high temperature begins (the second phase of the menstrual cycle, hyperthermic, “high”), which is caused by low levels of estrogen and high level progesterone. Pregnancy under the influence of progesterone also occurs entirely in a high temperature phase. The difference between the “low” (hypothermic) and “high” (hyperthermic) phases is 0.4-0.8 °C. Only when precise measurement basal body temperature can record 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 level of temperature in the second phase of the cycle.

Usually during menstruation the temperature remains at 37°C. During the period of follicle maturation (the first phase of the cycle), the temperature does not exceed 37°C. Just before ovulation it decreases (the result of the action of estrogen), and after it the basal temperature rises to 37.1 ° C and higher (the influence of progesterone). Until the next menstruation, the basal temperature remains elevated and decreases slightly 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 low amount of estrogen in the body and requires correction medicines 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 low progesterone levels and drugs for correction are also prescribed here hormonal levels. This should be done only after passing the appropriate hormone tests and a doctor’s prescription.

A persistent two-phase cycle indicates ovulation, which has taken place and the presence of a functionally active corpus luteum(correct rhythm of ovarian function).
The absence of a rise in temperature in the second phase of the cycle (monotonic curve) or significant temperature swings, 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).
Delayed 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 8-9 days after ovulation, which roughly corresponds to the time the fertilized egg implants into the uterine wall.

By charting your basal temperature, you can not only determine when you ovulate, but also find out what processes are occurring in your body.

Interpretation of basal temperature charts. Examples

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

Covering 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 the temperature could be affected by various negative factors(see rules for measuring temperature). This line does not allow any conclusions to be drawn from the graph and is for illustrative 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 center line and the three temperature values ​​must be at least 0.1 degrees on two days out of three 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 using 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 subsequent temperature by more than 0.2 degrees. Such temperature values ​​should not be taken into account when calculating ovulation if the overall basal temperature chart is normal.
The most optimal time For conception, the day of ovulation and 2 days before it are considered.

Menstrual cycle length
total length The normal cycle should 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 requires treatment by a gynecologist.

Second phase length
The basal temperature chart is divided into the first and second phases. The division takes place where the ovulation line (vertical) is marked. Accordingly, the first phase of the cycle is the segment of the graph before ovulation, and the second phase of the cycle is 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 individual norm. At the same time, in a healthy woman in different cycles there should be no 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 identified on the graphs and confirmed by subsequent hormonal studies- this is a failure of the second phase. If you measure your basal temperature over 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 lower limit(10 or 11 days), this may indicate insufficiency of the second phase.

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

An increase in basal temperature occurs when serum progesterone levels exceed 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 level progesterone in the second phase of the cycle. In addition, monophasic basal temperature is observed in approximately 20% of ovulatory cycles. A simple statement of biphasic basal temperature does not prove the normal function of the corpus luteum. Basal temperature also cannot be used to determine the time of ovulation, since even during luteinization of an unovulated follicle, a two-phase basal temperature is observed. Nevertheless, the duration of the luteal phase in accordance with basal temperature data and the low rate of rise in basal temperature after ovulation are accepted by many authors as criteria for diagnosing luteinization syndrome of a non-ovulating follicle.

Classic gynecological manuals describe five main types of temperature curves.

Normal two-phase cycle according to the basal temperature chart
Such graphs indicate an increase in temperature in the second phase of the cycle by at least 0.4 C; a noticeable “preovulatory” and “premenstrual” drop in temperature. The duration of the temperature increase after ovulation is 12-14 days. This curve is typical for a normal two-phase menstrual cycle.

The example graph 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 slight 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 examples of graphs below.

If such graphs are repeated from cycle to cycle, then this may indicate hormonal imbalances which are the cause of infertility.
Basal temperature begins to rise only shortly before menstruation, and there is no “premenstrual” drop in temperature. The second phase of the cycle can last less than 10 days. This curve is typical for a two-phase menstrual cycle with insufficiency of the second phase. See examples of graphs below.

Pregnancy in such a cycle is possible, but it is under threat from the very beginning. At this moment, the woman still cannot know about the pregnancy; even gynecologists would find it difficult to make a diagnosis at such a time. early. With such a schedule, we may not be talking about infertility, but about miscarriage. Be sure to contact your gynecologist if this schedule repeats for you for 3 cycles.

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

Each woman may have several anovulatory cycles per year - this is normal and does not require medical intervention, but if this situation repeats from cycle to cycle, then be sure to consult a gynecologist. Without ovulation, pregnancy is impossible!
A monotonous curve occurs when there is no pronounced rise throughout the entire cycle. This schedule is observed during an anovulatory (no ovulation) cycle. See examples of graphs below.

On average, a woman has one anovulatory cycle per year and there is no reason to worry in this case. But anovulatory schedules that are repeated from cycle to cycle are very serious reason consult 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 ranges; it does not fit into any of the types described above. This type of curve can be observed both with severe estrogen deficiency and depend on random factors. Examples of graphs are below.
A competent gynecologist will definitely require hormone tests and conduct an ultrasound examination before prescribing medications.

High basal temperature in the first phase

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

Estrogen deficiency
In the first phase of the cycle in female body The dominant hormone is estrogen. Under the influence of this hormone, the basal temperature before ovulation averages between 36.2 and 36.5 degrees. If the temperature in the first phase rises and remains above this level, 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 maintained at this level. To increase estrogen levels, gynecologists-endocrinologists will prescribe hormonal medications.

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

Using the example 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 days 17 and 18 of the cycle is insignificant. Fertilization in a cycle with such a schedule is very problematic.

Inflammation of the appendages
Another reason for the 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 graphs, calculating ovulation is difficult, since such a rise “masks” the ovulatory rise.

In the example graph, the temperature in the first phase of the cycle is kept at 37.0 degrees, the increase occurs sharply and also decreases sharply. A rise in temperature on the 6th day of the cycle can be mistakenly taken for an ovulatory rise, but in fact it most likely indicates inflammation. That's why it's so important to measure your temperature throughout your cycle to rule out a scenario where your temperature rises due to inflammation, then drops again, and then rises due to 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 start of menstruation and rises again to 37.0 degrees with the beginning of menstruation (less often on the 2-3rd day of the cycle), then this may indicate the presence of endometritis.

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 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.

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

The temperature with corpus luteum deficiency rises shortly before menstruation, and there is no “premenstrual” drop. This may indicate hormonal deficiency. The diagnosis is made based on a blood test for progesterone in the second phase of the cycle. If its values ​​are reduced, then the gynecologist usually prescribes a progesterone substitute: utrozhestan or duphaston. These drugs are taken strictly after ovulation. If pregnancy occurs, use continues until 10-12 weeks. Abrupt withdrawal of progesterone in the second phase during pregnancy can lead to the threat of termination of pregnancy.

Special attention you need to pay attention to charts with a short second phase. If the second phase is shorter than 10 days, then one can also judge that the second phase is insufficient.
Situations when the basal temperature remains elevated for more than 14 days occur during pregnancy, the formation of an ovarian corpus luteum cyst, as well as during an acute inflammatory process of the pelvic organs.

Estrogen-progesterone deficiency
If, in combination with low temperature in the second phase, your chart 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 an 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, just like 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 by clomiphene (clostilbegit) with the use of duphaston in the second phase of breastfeeding, the basal temperature graph, as a rule, becomes “normal” - two-phase, with a pronounced phase transition, with quite high temperature in the second phase, with characteristic “steps” (the temperature rises 2 times) and a slight drop. If the temperature graph during stimulation, on the contrary, is disrupted and deviates from 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 upon stimulation with clomiphene also occurs with individual sensitivity to the drug.

Special cases of 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 individual feature 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 follow the rules for measuring temperature and observe the described problems on your basal temperature chart in at least 2 cycles in a row, consult a doctor for additional examinations. Beware of your gynecologist making diagnoses based solely on charts. What you need to pay attention to:

• ◦anovulatory schedules
• regular cycle delays when pregnancy does not occur
• late ovulation and failure to become pregnant for several cycles
• controversial charts with unclear ovulation
• graphs with high temperature throughout the cycle
• graphs with low temperature throughout the cycle
• schedules with a short (less than 10 days) second phase
• graphs with high temperature in the second phase of the cycle for more than 18 days, without the onset of menstruation and negative test for pregnancy
• unexplained bleeding or heavy discharge in the middle of the 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
• charts with clearly defined ovulation, regular intercourse during ovulation and no pregnancy occurring 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 temperature drops (the temperature drops below 37°C).
• The rise in temperature in the middle of the cycle continues for more than 3 to 4 days.
• The second phase is short (less than 8 days).

Determining pregnancy by basal temperature

The method of determining pregnancy by basal temperature works provided there is ovulation in the cycle, since with some health problems the basal temperature can be elevated for an arbitrarily long time, and menstruation may be absent. A striking example Such a disorder is hyperprolactinemia, caused by 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 conditions and various disorders).

Fluctuations in basal temperature different phases The menstrual cycle is due to different levels of hormones responsible for phases 1 and 2.
During menstruation, 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, basal temperature decreases, and immediately after ovulation it increases 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 pregnancy.

This method of determining pregnancy works provided there is ovulation in the cycle, since with some health problems the basal temperature can be elevated for an arbitrarily long time, and menstruation may be absent. A striking example of such a disorder is hyperprolactinemia, caused by 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 pregnancy. A decrease in basal temperature during pregnancy may indicate a lack of hormones that maintain pregnancy and the threat of its termination.

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

It is possible that small discharge appears these days, which disappears within 1-2 days. This may be so-called implantation bleeding. When the egg implants into the inner lining of the uterus, the endometrium is damaged, which leads to minor discharge. But if you experience regular discharge in the middle of the cycle, and pregnancy does not occur, then you should contact a gynecology center.

A sharp decrease in temperature to the midline level 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 decrease from the middle of the second phase; with pregnancy, its production resumes again, which leads to temperature fluctuations. Secondly, during 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 retraction on the graph.

Your chart has become three-phase, which means that you see a rise in temperature on the chart, similar to ovulation, during the second phase of the cycle. This rise is again due to the increased production of the hormone progesterone after implantation.

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

Such early signs pregnancy, such as nausea, chest tightness, frequent urination, intestinal upset or just the feeling of pregnancy also do not provide an accurate answer. You may not be pregnant if you have all of these signs, or you may be pregnant without any symptoms.

All these signs can be a confirmation of pregnancy, but you should not rely on them, since there are many examples in which the signs were present, but pregnancy did not occur. Or, conversely, when pregnancy occurred there were no signs. The most reliable conclusions can be drawn if there is a clear rise in temperature on your chart, you had sexual 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.
Measuring basal temperature is one of the main methods of tracking fertility, recognized by the World Health Organization (WHO). You can read more about this in the WHO document “Medical eligibility criteria for the use of contraceptive methods” page 117.
When using the basal temperature method to protect against... unwanted pregnancy, you need to take into account that not only the days of ovulation according to the basal temperature schedule can be dangerous. Therefore, during 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.

Attention! Making any diagnoses based solely on basal temperature charts is impossible. Diagnoses are made based on additional examinations performed by a gynecologist.

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

Why measure basal 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 demands 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 Marshall and refers to research techniques that are based on the biological effect of sex hormones, namely on the hyperthermic (increase in temperature) action of progesterone on the thermoregulation center. Measuring 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 constructed; an analysis of basal temperature graphs is given below.

Measuring basal temperature and charting is recommended in gynecology in the following cases:

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

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

Do you want to increase your chances of pregnancy?
You are experimenting with methods of planning the gender of your child
You want to observe your body and understand the processes taking place in it (this can help you communicate with specialists)

Experience shows that many women perceive the doctor’s demands 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 this happen (accordingly, highlight “dangerous” days for the purpose of protection or, conversely, the possibility of getting pregnant);
Did ovulation occur after the egg matured?
Determine the quality of your endocrine system
Suspect gynecological problems, such as endometritis
When to expect your next menstruation
Whether pregnancy occurred due to delay or unusual menstruation;
Assess how correctly the ovaries secrete hormones according to the phases of the menstrual cycle;

A graph of basal temperature, drawn up according to all measurement rules, can show not only the presence of ovulation in a 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 of conception, as well as conclusions about hormonal disorders. Only a gynecologist can give an accurate assessment of your basal temperature chart. Drawing up 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 gynecologist’s diagnosis based solely on the 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 at the armpit. A general increase in temperature as a result of illness, overheating, physical activity, eating, stress, naturally affects the basal temperature readings and makes them unreliable.

Thermometer for measuring basal temperature.

You will need a regular medical thermometer: mercury or electronic. The basal temperature is measured with a mercury thermometer for five minutes, but the electronic thermometer must be removed after the signal about the end of the measurement. After it squeaks, the temperature will continue to rise for some time, since the thermometer records the moment when the temperature rises above very slowly (and don’t listen to the nonsense about the thermometer not being in good contact with the muscles of the anus). The thermometer must be prepared in advance, in the evening, by placing it next to the bed. Do not place mercury thermometers under your pillow!

Rules for measuring basal temperature.

You should measure your basal temperature every day if possible, including on your period.

Measurements can be taken in the mouth, vagina or rectum. The main thing is that the measurement location does not change throughout the entire cycle. Measuring armpit temperature does not provide accurate results. With the oral method of measuring basal temperature, you place the thermometer under your tongue and measure for 5 minutes with your mouth closed.
When using the vaginal or rectal method of measurement, insert the narrow part of the thermometer into the anus or vagina, the measurement duration is 3 minutes. Measuring temperature in the rectum is the most common.

Measure your basal temperature in the morning, immediately after waking up and before getting out of bed.

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

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

You can use either a digital or a mercury thermometer to measure. It is important not to change the thermometer during one cycle.
If you use a mercury thermometer, shake it off before going to sleep. The effort you use to shake off the thermometer immediately before measuring your basal temperature can affect your temperature.

Basal temperature is measured while lying still. Do not make unnecessary movements, do not turn, activity should be minimal. Do not under any circumstances get up to take a thermometer! Therefore, it is better to prepare it in the evening and place it near the bed so that you can reach the thermometer with your hand. Some experts advise taking the measurement without even opening your eyes, since daylight can increase the release of certain hormones.

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

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

The schedule must indicate the reasons that could lead to an increase in basal temperature (acute respiratory infections, inflammatory diseases, etc.).

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

In case of illnesses accompanied by elevated body temperature, your basal temperature will be uninformative and you can stop taking measurements for the duration of your illness.

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

After drinking 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) recording table should contain the following lines:

Day of the month
Cycle day
BT
Notes: Heavy or moderate discharge, abnormalities that can affect BT: general illness, including fever, diarrhea, intercourse in the evening (and even more so in the morning), drinking alcohol the day before, measuring BT at unusual times, going to bed late (for example, she went to bed at 3 o’clock and measured it at 6), taking sleeping pills, stress, etc.

All factors that in one way or another could affect the change in basal temperature are entered in the “Notes” column.

This form of recording greatly 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 changes during the cycle under the influence of hormones.

During the maturation of the egg against the background of a high level of estrogen (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 hour, ovulation occurs. After ovulation, a phase of high temperature 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 occurs entirely in a high temperature phase. The difference between the “low” (hypothermic) and “high” (hyperthermic) phases is 0.4-0.8 °C. Only with an accurate measurement of basal body temperature can one record 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 level of temperature in the second phase of the cycle.

Usually during menstruation the temperature remains at 37°C. During the period of follicle maturation (the first phase of the cycle), the temperature does not exceed 37°C. Just before ovulation it decreases (the result of the action of estrogen), and after it the basal temperature rises to 37.1 ° C and higher (the influence of progesterone). Until the next menstruation, the basal temperature remains elevated and decreases slightly 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 low amount of estrogen in the body and requires correction with medications 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 low progesterone levels and drugs are also prescribed to correct hormonal levels. This should be done only after passing the appropriate hormone tests and a doctor’s prescription.

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 (monotonic curve) or significant temperature swings, 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).
Delayed 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 8-9 days after ovulation, which roughly corresponds to the time the fertilized egg implants into the uterine wall.

By charting your basal temperature, you can not only determine when you ovulate, but also find out what processes are occurring in your body.

Interpretation of basal temperature charts. Examples

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

Covering 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 the temperature could be affected by various negative factors (see rules for measuring temperature). This line does not allow any conclusions to be drawn from the graph and is for illustrative 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 center line and the three temperature values ​​must be at least 0.1 degrees on two days out of three 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 using 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 subsequent temperature by more than 0.2 degrees. Such temperature values ​​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 length of the cycle 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 requires treatment by a gynecologist.

Second phase length

The basal temperature chart is divided into the first and second phases. The division takes place where the ovulation line (vertical) is marked. Accordingly, the first phase of the cycle is the segment of the graph before ovulation, and the second phase of the cycle is 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 the individual norm. At the same time, in a healthy woman in different cycles there should be no 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 identified on the graphs and confirmed by subsequent hormonal studies is the failure of the second phase. If you measure your basal temperature over 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 insufficiency of the second phase.

Temperature difference

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

An increase in basal temperature occurs when serum progesterone levels exceed 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 observed in approximately 20% of ovulatory cycles. A simple statement of biphasic basal temperature does not prove the normal function of the corpus luteum. Basal temperature also cannot be used to determine the time of ovulation, since even during luteinization of an unovulated follicle, a two-phase basal temperature is observed. Nevertheless, the duration of the luteal phase in accordance with basal temperature data and the low rate of rise in basal temperature after ovulation are accepted by many authors as criteria for diagnosing luteinization syndrome of a non-ovulating follicle.

Classic gynecological manuals describe five main types of temperature curves.

Such graphs indicate an increase in temperature in the second phase of the cycle by at least 0.4 C; a noticeable “preovulatory” and “premenstrual” drop in temperature. The duration of the temperature increase after ovulation is 12-14 days. This curve is typical for a normal two-phase menstrual cycle.

The example graph 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 slight 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 examples of graphs below.

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

Basal temperature begins to rise only shortly before menstruation, and there is no “premenstrual” drop in temperature. The second phase of the cycle can last less than 10 days. This curve is typical for a two-phase menstrual cycle with insufficiency of the second phase. See examples of graphs below.

Pregnancy in such a cycle is possible, but it is under threat from the very beginning. At this moment, the woman cannot yet know about the pregnancy; even gynecologists would find it difficult to make a diagnosis at such an early stage. With such a schedule, we may not be talking about infertility, but about miscarriage. Be sure to contact your gynecologist if this schedule repeats for you for 3 cycles.

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

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

A monotonous curve occurs when there is no pronounced rise throughout the entire cycle. This schedule is observed during an anovulatory (no ovulation) cycle. See examples of graphs below.

On average, a woman has one anovulatory cycle per year and there is no reason to worry in this case. But anovulatory patterns that are repeated from cycle to cycle are a very serious reason to consult 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 ranges; it does not fit into any of the types described above. This type of curve can be observed both with severe estrogen deficiency and depend on random factors. Examples of graphs are below.

A competent gynecologist will definitely require hormone tests and conduct an ultrasound examination before prescribing medications.

High basal temperature in the first phase

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

Estrogen deficiency

In the first phase of the cycle, the hormone estrogen dominates in the female body. Under the influence of this hormone, the basal temperature before ovulation averages between 36.2 and 36.5 degrees. If the temperature in the first phase rises and remains above this level, 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 maintained at this level. To increase estrogen levels, gynecologists-endocrinologists will prescribe hormonal medications.

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

Using the example 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 days 17 and 18 of the cycle is insignificant. Fertilization in a cycle with such a schedule is very problematic.

Inflammation of the appendages

Another reason for the 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 graphs, calculating ovulation is difficult, since such a rise “masks” the ovulatory rise.

In the example graph, the temperature in the first phase of the cycle is kept at 37.0 degrees, the increase occurs sharply and also decreases sharply. A rise in temperature on the 6th day of the cycle can be mistakenly taken for an ovulatory rise, but in fact it most likely indicates inflammation. That's why it's so important to measure your temperature throughout your cycle to rule out a scenario where your temperature rises due to inflammation, then drops again, and then rises due to 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 start of menstruation and rises again to 37.0 degrees with the beginning of menstruation (less often on the 2-3rd day of the cycle), then this may indicate the presence of endometritis.

Characteristically, the temperature drops before menstruation and rises with the onset of next cycle. If there is no drop in temperature before the start of menstruation in the first cycle, i.e. the temperature remains at this level, then pregnancy can be assumed, despite the bleeding that has begun. Take a pregnancy test and contact a gynecologist who will perform an ultrasound to make 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 assessing the entire graph, and not a separate temperature in the first phase. For diseases accompanied by high or elevated body temperature, measuring basal temperature, much less judging its nature and analyzing the graph, makes no sense.

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 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.

Corpus luteum deficiency

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

The temperature with corpus luteum deficiency rises shortly before menstruation, and there is no “premenstrual” drop. This may indicate hormonal deficiency. The diagnosis is made based on a blood test for progesterone in the second phase of the cycle. If its values ​​are reduced, then the gynecologist usually prescribes a progesterone substitute: utrozhestan or duphaston. These drugs are taken strictly after ovulation. If pregnancy occurs, use 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 that the second phase is insufficient.

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

Estrogen-progesterone deficiency

If, in combination with low temperature in the second phase, your chart 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 an 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, just like 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 by clomiphene (clostilbegit) with the use of duphaston in the second phase of the cycle, 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” (temperature rises 2 times) and slight depression. If the temperature graph during stimulation, on the contrary, is disrupted and deviates from 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 upon stimulation with clomiphene also occurs with individual sensitivity to the drug.

Special cases of 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 follow the rules for measuring temperature and observe the problems described on your basal temperature chart in at least 2 cycles in a row, consult a doctor for additional examinations. Beware of your gynecologist making diagnoses based solely on charts. What you need to pay attention to:

anovulatory schedules
regular cycle delays when pregnancy does not occur
late ovulation and failure to become pregnant for several cycles
controversial charts with unclear ovulation
graphs with high temperature throughout the cycle
graphs with low temperature throughout the cycle
schedules with a short (less than 10 days) second phase
graphs with a 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
charts with clearly defined ovulation, regular intercourse during ovulation and no pregnancy occurring 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 temperature drops (the temperature drops below 37°C).
The rise in temperature in the middle of the cycle continues for more than 3 to 4 days.
The second phase is short (less than 8 days).

Determining pregnancy by basal temperature

The method of determining pregnancy by basal temperature works provided there is ovulation in the cycle, since with some health problems the basal temperature can be elevated for an arbitrarily long time, and menstruation may be absent. A striking example of such a disorder is hyperprolactinemia, caused by 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 conditions 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, 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, basal temperature decreases, and immediately after ovulation it increases 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 pregnancy.

This method of determining pregnancy works provided there is ovulation in the cycle, since with some health problems the basal temperature can be elevated for an arbitrarily long time, and menstruation may be absent. A striking example of such a disorder is hyperprolactinemia, caused by 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 pregnancy. A decrease in basal temperature during pregnancy may indicate a lack of hormones that maintain pregnancy and the threat of its termination.

When pregnancy occurs, in most cases, implantation occurs 7-10 days after ovulation - 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 or absence of implantation either on the basis of a chart or with the help of ultrasound at an appointment with a gynecologist. However, there are several signs that may indicate implantation has taken place. All these signs can be detected 7-10 days after ovulation:

It is possible that small discharge appears these days, which disappears within 1-2 days. This may be so-called implantation bleeding. When the egg implants into the inner lining of the uterus, the endometrium is damaged, which leads to minor discharge. But if you experience regular discharge in the middle of the cycle, and pregnancy does not occur, then you should contact a gynecology center.

A sharp decrease in temperature to the midline level 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 decrease from the middle of the second phase; with pregnancy, its production resumes again, which leads to temperature fluctuations. Secondly, during 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 retraction on the graph.

Your chart has become three-phase, which means that you see a rise in temperature on the chart, similar to ovulation, during the second phase of the cycle. This rise is again due to the increased production of the hormone progesterone after implantation.

The example graph shows 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, intestinal upset or just the feeling of pregnancy also do not provide an accurate answer. You may not be pregnant if you have all of these signs, or you may be pregnant without any symptoms.

All these signs can be a confirmation of pregnancy, but you should not rely on them, since there are many examples in which the signs were present, but pregnancy did not occur. Or, conversely, when pregnancy occurred there were no signs. The most reliable conclusions can be drawn if there is a clear rise in temperature on your chart, you had sexual 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.

Measuring basal temperature is one of the main methods of tracking fertility, recognized by the World Health Organization (WHO). You can read more about this in the WHO document “Medical eligibility criteria for the use of contraceptive methods” page 117.

When you use the basal temperature method to protect against unwanted pregnancy, you need to take into account that not only the days of ovulation according to the basal temperature schedule can be dangerous. Therefore, during 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 your basal temperature chart, which you can print out and show to your doctor. You can download it from the link: schedule form.

The charts are discussed on the forum

Attention! Making any diagnoses based solely on basal temperature charts is impossible. Diagnoses are made based on additional examinations performed by a gynecologist.

Charting basal temperature is one of the methods for assessing the functioning of the reproductive system, which is available to almost every woman.

Maintaining a graph and deciphering it require compliance with certain rules and subtleties, otherwise there is a high probability of obtaining distorted results.

Keeping a graph of basal temperature allows you to determine the correct functioning of the female ovaries and identify a number of problems that affect the ability to conceive a child.

Using the graph you can determine:

• egg maturation time;
• in a particular cycle or its absence;
• favorable and unfavorable days for conception;
• presence of hormonal problems;
• diseases of the pelvic organs;
• the reason for the delay of the next menstruation.

The measurement results will be informative only if the graphs were kept for at least three menstrual cycles.

Some gynecologists observe for at least six months to accurately diagnose. For correct interpretation it is necessary. Otherwise, the graph data will not be indicative.

Building a BT schedule during pregnancy

The method of maintaining basal temperature charts is becoming increasingly widespread due to its accessibility. All you need is a thermometer, a squared notebook and a pencil.

Basal temperature is measured at anus every day, immediately after waking up. The resulting value is entered into the table and marked on the graph.

The graph shows daily measurement results during the menstrual cycle (not a month). A normal cycle is considered to last from 21 to 35 days. The beginning of the cycle is considered the first day of menstruation (and not its end, as some people think).

Each menstrual cycle should have its own basal temperature curve.

On vertical axis degrees are marked on the graph (1 cell = 0.1 °C), on horizontal axis– days of the cycle and the date corresponding to this day. The resulting temperature value is marked on the graph by the corresponding point, after which adjacent points are connected to each other. Thus, a curve of changes in basal temperature during the cycle is constructed.

Factors that may affect the reliability of the measurement should be noted next to the corresponding day of the cycle.

These include ailments, alcohol consumption, sex shortly before measurement, insomnia, stress, and moving. Unusual temperature fluctuations caused by these factors can be excluded from the curve.

Interpretation of different types of graphs using examples: high, low and normal temperature

The graph shows the dependence of basal temperature on the phases of the menstrual cycle. In the first phase, called the follicular phase, several follicles mature. This period passes under the influence of estrogen, the temperature varies between 36.4-36.8 °C.

The first phase takes about half of the cycle. At this time, out of several follicles, one remains, and the egg matures in it.

Then the follicle bursts and the egg is released from the ovary, that is, ovulation occurs.

Before ovulation, basal temperature drops to its minimum.

The second phase of the cycle begins, during which a corpus luteum appears in place of the burst follicle. Its cells synthesize a hormone, under the influence of which a jump in basal temperature occurs by 0.4-0.8 °C. This phase is called the luteal phase.

If conception does not occur during the cycle, progesterone levels drop and basal temperature decreases slightly 2-3 days before the upcoming menstruation.

Normal two-phase schedule

The basal temperature chart for a healthy woman has clearly demarcated phases of the menstrual cycle: follicular with a low basal temperature and luteal, which is distinguished by an increase in temperature. Before ovulation and the onset of menstruation, a drop in temperature occurs.

The graph is divided into phases by the ovulation line. The follicular phase is the segment of the curve from the first day of the cycle to ovulation, the luteal phase is from ovulation to the end of the cycle. The duration of the first phase of the cycle is an individual characteristic of each woman and there are no clear requirements for it. The second phase should normally last 12-16 days.

If, over several months of observation, the length of the luteal phase does not fall within this range, a consultation with a gynecologist is necessary. This may indicate a failure of the second phase.

In a healthy woman, the duration of each phase should not vary significantly in different menstrual cycles.

Normally, the difference in average temperatures between cycle phases should be 0.4 °C or more.

To determine it, you need to add up all the basal temperature values ​​in the first phase and divide by the number of days in the phase. The average value of basal temperature in the second phase of the cycle is calculated in the same way.

Then the first is subtracted from the second indicator obtained; the result obtained characterizes the difference in average temperatures. If it is below 0.4 °C, it may be a sign of the presence hormonal imbalance in organism.

Basal temperature chart at conception

If conception occurs during the menstrual cycle, then the basal temperature in the second phase behaves somewhat differently. It is known that after ovulation, BBT normally remains above 37 °C. However, in the cycle when pregnancy occurred 7-10 days after ovulation, the temperature drops below 37 °C. The so-called implantation retraction is observed.

Estrogen deficiency

In the case of estrogen deficiency, the graph does not divide the cycle into clear phases, since low level estrogen provokes an increase in temperature in the follicular phase of the cycle. The curve is chaotic, it is impossible to determine the date of ovulation.

Conception in this case is unlikely; you should consult a gynecologist. If estrogen deficiency is confirmed after additional examinations, the patient will be prescribed treatment with hormonal drugs.

Anovulatory cycle

In the absence of ovulation, the graph looks like a monotonous curve without division into phases. In the second phase of the menstrual cycle, the basal temperature remains low and does not exceed 37 °C. In such a cycle, the formation that synthesizes progesterone does not occur, so the basal temperature does not increase in the second half of the cycle.

A couple of anovulatory cycles per year is normal, but if the situation repeats for several months in a row, you should consult a doctor. Pregnancy without ovulation is impossible, so it is necessary to find the root of the problem together with a gynecologist.

The difference in average temperatures between the phases of the cycle is 0.2-0.3 °C. If such graphs are built over several cycles in a row, this may be a sign of infertility due to hormonal imbalances.

If the corpus luteum does not function effectively enough and does not produce the required amount of progesterone, the temperature in the second phase of the cycle rises slightly. In this case, the duration of the second phase is reduced to 10 days and there is no drop in basal temperature before the onset of menstruation.

If the corpus luteum is insufficient, fertilization of the egg is possible, but there is a high risk of its rejection in the same cycle.

To confirm the diagnosis, a woman needs to undergo a blood test for progesterone.

Diagnosed corpus luteum deficiency is corrected by taking artificial progesterone analogs (“” or “”) in the luteal phase of the cycle.

Prolactin is the hormone responsible for pregnancy and breast-feeding. Normally, in a non-pregnant woman it is absent or its level is extremely low.

If for certain reasons it increases, the basal temperature chart becomes identical. In this case, there may be a lack of menstruation.

Inflammation of the appendages

Availability inflammatory process can be suspected by the temperature jump in the first segment of the graph. A high basal temperature is observed in the first phase of the cycle.

It rises sharply to 37 °C and after a few days decreases sharply. Such a jump can be mistaken for an ovulatory rise in temperature, so with this type of graph it can be difficult to determine the onset of ovulation.

Endometritis

Normal upon arrival critical days basal temperature should decrease. With endometritis (inflammation of the uterine mucosa), there is a drop in temperature before the onset of menstruation and a rise to 37 °C in the first phase of the menstrual cycle.

Maintaining basal temperature charts - accessible and safe method definitions of favorable and unfavorable days for conception. But due to its high sensitivity it requires a responsible and competent approach, otherwise maintaining a schedule loses its practical meaning.

Even if the graph is constructed correctly, you need to remember that the final diagnosis is never made solely on the basis of analysis of the curve data. Any diagnosis must be confirmed by tests and additional studies.

Anovulatory schedule let's say 1-2 times a year even completely healthy women. In other cases it is about hormonal imbalance. You should immediately visit a doctor to begin timely treatment.

For endometritis

By analyzing basal temperature, you can identify the presence of a disease such as endometritis. Normal at the beginning of a new cycle the temperature should drop. If during menstrual flow If BT increases and remains at this level, then this is a clear symptom of the presence of the disease.

Along with this, the appearance of other symptoms of the disease is noted. These include the following:

• Painful sensations during sexual intercourse.
• Feeling worse.
• Cycle disruption.
• Purulent discharge.
• Uterine bleeding.

It is not recommended to determine deviations from the BT schedule yourself. This should be done Therapist. Treatment is prescribed based on the results of tests and other studies.