What will basal temperature tell you during pregnancy? Measuring basal temperature (BT). Rules

Just 15 years ago, measuring BT was considered one of the main diagnostic methods for assessing women's reproductive health. After all, the basal temperature of a non-pregnant woman is fundamentally different from the BT of a pregnant woman. A “healthy” temperature chart is completely different from that of a girl with “feminine” problems.

Now this method has given way to other, more modern and accurate diagnostic methods. Gynecologists prefer to prescribe ultrasound and hormonal tests for patients. However, the BT method can still tell a lot both to the girl herself and her doctor.

unsuccessful attempts to conceive a child over a long period of time;
suspicion of hormonal imbalance and changes in the menstrual cycle;
probable infertility of one of the partners;
calculation using a chart of the most favorable days for conception, when ovulation occurs (the release of an egg ready for fertilization from a mature follicle);
control over the processes occurring in a woman’s body;
diagnosis of anovulatory cycles.

BT is measured in the morning, after a full night's rest (when healthy sleep lasted at least 6-7 hours), in a state of complete rest and without getting out of bed. As a rule, the most accurate results can be obtained if you measure basal temperature with a regular mercury thermometer in the rectal passage, but experts also do not deny the information content of measurements obtained by measuring indicators in the oral cavity or vagina.

Based on the results of which a special schedule is drawn up. Only a qualified specialist can give a competent assessment of the basal temperature chart. However, the girl herself can understand a lot.

Cycle phases on the chart

The normal monthly cycle of a woman who is not pregnant consists of two main periods: the follicular and luteal phases. In the first phase of the cycle, which begins with the onset of menstruation, the woman’s body actively synthesizes estrogen hormones, which have a positive effect on the maturation of the egg and the proliferation of the uterine endothelium. This period is characterized by consistently low BT indicators on the graphs, and therefore is called hypothermic.

Approximately in the middle of the monthly cycle, an egg matures in the follicle. Its release from the ovary or ovulation is accompanied by a change in the woman’s hormonal levels, after which progesterone, the main hormone of pregnancy, normally begins to be produced. This biologically active substance, influencing thermoregulation centers in the brain, provokes an increase in temperature by about 0.4-0.6 degrees. If fertilization does not occur, progesterone levels begin to decrease, menstruation begins and the body again enters the follicular phase of the cycle.

Temperature norm

Basal temperature in the absence of pregnancy has its own characteristic features, which are clearly visible on correctly drawn up graphs of the period without conception. The norm is when in the first phase the temperature ranges from 36.3 to 36.6, and in the second it increases by about 0.4-0.6 and is already 36.9-37.1 degrees and higher.

So, what should be the basal temperature for non-pregnant women? The following features are typical for a non-pregnant basal temperature chart:

decrease in BT with the onset of menstruation to a level of 36.3-36.5;
stable level of basal temperature throughout the follicular phase;
an increase in BT levels approximately two weeks before the expected menstruation;
the presence of ovulation relapse or a decrease in basal temperature by 0.1 before the release of the reproductive gamete from the ovary;
increase in indicators during ovulation to 36.9-37.1;
the temperature difference between the two phases should not exceed 0.4-0.5;
decrease in temperature level to 36.7-36.8 one or two days before the start of menstruation.

Naturally, the graph of basal temperature in the absence of pregnancy differs in many ways from the curves obtained as a result of measuring BT in women who are already carrying a baby.

The main feature of schedules without pregnancy is a decrease in temperature levels in the last few days of the cycle, that is, a decrease in progesterone activity. In addition, the basal temperature, if there is no pregnancy (unlike the indicators of women expecting a child), has a two-level appearance, falling in the middle of the cycle and a gradual rise in the temperature curve in its second period.

Deviations from the norm

Each woman normally experiences menstrual cycles without the release of a mature egg, which are called anovulatory, approximately twice a year. On such charts, the line is constantly at the same level, without dips or sharp rises. Anovulatory cycles are characterized by the following features:

absence of a difference in basal temperature in the middle of the cycle on the graphs. The situation when is confirmation of the absence of ovulation;
in the second phase, no increase in temperature level is recorded, since pregnancy does not form, synthesizing progesterone.

Basal temperature charts will allow you to suspect some diseases of the female genital area. Temperature jumps above 37.0 in the first phase of the cycle indicate the development of an inflammatory process in the ovaries or uterus. And if there is a lack of hormones, a relative increase in it will be recorded in the first period of the cycle and a decrease in the second.

However, it is important to remember that any deviations from the norm on the graph are just a reason to contact a specialist. Temperature measurement itself is only an auxiliary, and not the main diagnostic method. Perhaps your fears are completely unfounded. Much more reliable are laboratory tests, ultrasound and other studies that your doctor will prescribe.

Measuring basal temperature is one of the methods for examining the female body, in particular, monitoring the functioning of the reproductive system.

Fertility issues in the monthly cycle

Childbirth is the natural purpose of the female body. Therefore, the functional features of physiological processes are clearly organized, like everything in nature, which relates to issues of reproduction. The range of development fits into one menstrual cycle.

Important! The menstrual cycle is the period from the beginning of one period to the beginning of the next. It is at this time that conditions for conception are created, and they are realized or such a possibility is excluded.

The monthly cycle goes through 2 physiological phases:

Follicular.
At this stage, the follicles enlarge, and the maturation of the egg ends, which prepares for contact with the seminal fluid. The phase starts on the 1st day of menstruation and lasts, on average, half the cycle, until the egg is released from the follicle membranes. Before ovulation (rupture of the follicular membranes), fertilization is impossible, so the phase is not considered predisposing to conception. During this period, the body is saturated with female sex hormones - estrogens, which stimulate egg maturation.
Luteal.
It occurs 1–2 days before fertilization and ends with the next menstruation or pregnancy. Lasts at least 10 days, more often 12 - 16, conception is possible in the first 2 days. The intake of the hormonal secretion of the corpus luteum, progesterone, into the organs increases, which contributes to the successful development of pregnancy.

The duration of each phase is influenced by many factors:

the woman’s body’s resistance to stress;
susceptibility to infections;
hormonal support - this indicator is the most important, because a decrease or increase in the level of hormones in any phase reduces the likelihood of conception and requires correction.

Measuring basal temperature over several cycles in a row provides a fairly indicative picture of women's health and fertility.

Temperature data tracking

Tracking the correct sequence of phases in the cycle allows you to most likely plan a pregnancy and implement the plan or avoid unwanted conception.

The following indicators are characteristic of a well-functioning sexual sphere of a woman:

after menstruation (more precisely, from the 2nd - 3rd day of the first phase), the basal temperature is set at a slightly lower level - 36.2 - 36.5°C;
after the release of the egg (in the middle of the cycle), there is a noticeable increase to 37 ° C or slightly higher (luteal phase);
at the end of the first phase, 1 - 2 days before ovulation, a one-day decline in indicators is noted (0.1 - 0.2 ° C);
before menstruation and at the beginning of menstruation, the temperature remains at the level of the second phase, and then decreases, a new cycle begins - if during menstruation the numbers do not fall, then, most likely, conception has occurred, the fertilized egg has implanted and pregnancy develops.

Important! With a natural method of contraception based on the timing of ovulation, in the first phase of the cycle it is recommended to take additional protective measures, because The maturation of the egg does not always occur at the same time.

the textbook correct chart divides the monthly cycle into two approximately equal parts (in duration) - in the first part of the monitored period the numbers are noticeably lower than in the second;
a temperature that is elevated in the initial phase (but does not reach the levels of the second phase) indicates a possible lack of estrogen, which complicates the maturation of the egg, and a significantly reduced temperature indicates an excess, which also does not contribute to the correct formation of conditions for fertilization;
a low temperature in the second phase demonstrates a lack of progesterone - conception is possible at this time, but fertilization does not always end in pregnancy, and when the fertilized egg is implanted, there is a possibility of miscarriage;
in the absence of a jump in temperature and maintaining it at approximately the same level throughout the entire cycle, they speak of a monophasic course of the period - an anovulatory cycle, which is not a pathology if it happens 1-2 times a year, and if it occurs regularly, it indicates infertility.

Important! Only a doctor can make a diagnosis of infertility. For this indicator, temperature measurement graphs are not enough - additional research and analysis is needed.

A comparison of the temperature indicators of a normal and anovulatory cycle is presented in the table.

Cycle day	Norm	Anovulatory cycle
1	36,9	36,6
2	36,8	36,6
3	36.7	36.7
4	36.5	36.8
5	36.3	36,6
6	36.4	36.5
7	36.4	36.7
8	36.3	36.7
9	36.4	36.6
10	36.5	36.7
11	36.4	36.6
12	36.2	36.5
13	36.4	36.6
14	36.4	36.7
15	36.8	36.7
16	36.9	36.8
17	37.1	36.9
18	37.0	36.8
19	37.1	36.8
20	37.1	36.9
21	36.9	36.8
22	37.0	36.7
23	37.1	36.7
24	37.1	36.8
25	37.0	36.7
26	37.0	36.7
27	37.0	36.6
28	37.0	36.6
	menstruation
	time of expected ovulation

Basal temperature is the body temperature at rest, when it is possible to calculate the state of the gonads and the system as a whole. It shows the lowest temperature readings, which are observed only at rest. This helps many women understand what phase they are in. Correct measurements and schedule during the cycle help determine the period of ovulation when you can conceive a child or, conversely, have unprotected sex without consequences.

There are three successive phases of the menstrual cycle:

Follicular.
Ovulation.
Luteal.

At each stage there is a different level of hormones, which is reflected in the basal temperature. To obtain accurate data, it is necessary to take accurate measurements in the rectum, vaginal or.

Measuring rules

The main rules of measurement, which are noted on the website, are as follows:

Take your temperature no more than 30-60 minutes after waking up.
The duration of sleep before measurements should be at least 3 hours. A shorter rest period may skew the results.
Take measurements at the same time.
Take your temperature while lying down, do not sit down.

If you take the temperature later, you may make a mistake. Notes should be made in the records at what time the measurements were taken. Every hour the temperature increases by 0.1 degrees.

The same thermometer should be used throughout the entire cycle to obtain more accurate data. It is better to use a digital thermometer that makes a sound when the measurement is completed. However, when using a mercury thermometer, you should hold it for 5 minutes. At the same time, it is not advisable to rise or move suddenly.

It is better to take measurements throughout the month, including monthly days, in order to create a schedule.

BT schedule

The basal temperature (BT) chart is drawn from the beginning of the last to the beginning of the new menstruation and then a new one is drawn. The dividing line is the period of ovulation, when the egg is released from the ovary. She divides the stages into before and after. Ovulation occurs in the middle of the menstrual cycle - on days 12-16.

The average cycle length is 28 days. This is the period from the start of bleeding of the previous menstruation to the first day of bleeding of the next. In some cases, this period increases to 35 days. Sometimes the last point in the BT chart is 21 days.

What does the BT chart show?

Days of ovulation, which allows you to determine when to conceive.
Causes of infertility that only a doctor can identify.
Causes of delayed or supposed menstrual flow.
Identify sexually transmitted diseases, such as endometritis.

First phase

The follicular first phase is also called hypothermic, while the luteal phase is hyperthermic. From the names it becomes clear that in the first period the body temperature is slightly lower, and in the second – increased. In the follicular phase, a follicle is formed in which the egg matures. Estrogen is produced by the ovaries. The normal temperature during this period is up to 37°C. This is favorable for pregnancy.

Elevated temperatures during this period become the reasons why conception does not occur. If in the first phase the temperature remains at 37 degrees, and the basal temperature on the 17th day reaches 37.5 degrees, then insemination becomes problematic, even if the sperm has penetrated the female reproductive system.

Second phase

Ovulation is difficult to detect. In the second phase, the temperature decreases, and the next day it increases by 0.4-0.5 ° C. She stays like this until her period. On average, the second phase lasts 14 days.

A decrease in basal temperature during implantation indicates the activation of estrogen - hormones that affect the temperature inside the reproductive system. This decrease occurs for several hours, and then increases again.

The duration of the luteal phase can be short - 10-12 days, which indicates its insufficiency and inability to bear a fetus. A longer phase may indicate the appearance of a cyst in the corpus luteum or the beginning of pregnancy. Only a doctor can decipher the data.

Ovulation occurs somewhere in the middle of the cycle. Sometimes it may not happen at all. Its presence is indicated by an increase in temperature.

Indicators in the first phase

In the first phase, estrogens predominate, which control the temperature of the reproductive system. Normal values are 36.2-36.5°C. If during this period the temperature rises to 36.5-36.8 ° C, then this indicates insufficient estrogen levels. In this case, gynecologists prescribe hormone therapy.

If the increase in temperature during the follicular period occurred within one day, then you should not worry. No pathologies can occur during such a period. Deviations should be judged not by a single indicator, but by the entire schedule, which is drawn up many times.

Indicators in the second phase

The second phase can also be marked by high temperatures. This indicates estrogen deficiency. After the egg leaves the follicle, the temperature rises to 37°C or more, which interferes with conception. The mark of 36.8 degrees is observed very rarely.

Rectal measurements exceed those in the first phase by 0.4 degrees. This is considered normal. Less significant differences indicate problems that need attention.

Every woman's body is unique. He is not required to meet clear indicators. Sometimes a high or low temperature is a feature, not a disease. Measurement methods should also be taken into account. Differences of 0.2 degrees are quite normal.

Impact factors

It is necessary to take into account factors influencing BT indicators. They are:

Drinking alcohol.
Sexual relations before dawn or at night.
Inflammation in the leg area.
Stress.
Various diseases.
Sleeping with a heating pad under an electric blanket.

These factors should be noted in your notebook where you keep your BT chart. Gynecologists advise taking daily measurements for at least 3 months, which will help identify more accurate data and features.

If a woman wants to more accurately determine the day of ovulation, then she should take daily measurements and write them down in a notebook for six months, or better yet, a year. In this case, you should stop taking hormonal medications and the contraceptive device. Only the use of a condom is allowed.

Rising temperature as an indicator of pregnancy

All manipulations are done for the sake of conception. A rising temperature may be an indicator that pregnancy has begun. This becomes clear when, from the moment of ovulation until the onset of menstruation (when they should begin), a high temperature is noted. It rises to 37°C or more and does not subside. This indicator becomes unambiguous if such a high temperature is noted in the period before the onset of menstruation and its delay.

In the second phase, BT can also be high in the absence of pregnancy. It rises to 37 degrees and above and stays there. Its decrease occurs the day before the start of menstruation. Accordingly, if there is a delay and BT is high, then we can talk about pregnancy. Therefore, you should focus not only on pregnancy tests, but also on internal temperature indicators.

Gynecologists recommend waiting for a delay so that breast disease and high temperature before menstruation are not misleading. These factors are normal before normal menstruation. However, a delay in combination with such symptoms may already indicate the beginning of pregnancy.

Temperature changes during other processes

You should listen to your body. A situation may arise when a change in temperature indicates other processes, for example, a miscarriage. In this case, menstruation is scanty and BT is high. You should take a pregnancy test and visit a gynecologist.

An increase in basal temperature on the 22nd day and its absence before or on the first day of menstruation may be an individual feature or indicate inflammatory processes in the body.

If BT drops on day 25, then this indicates upcoming menstruation. Everything in a woman’s body happens normally.

Forecast

Basal temperature, of course, can help a woman determine the days of ovulation and even find out in advance that she is pregnant, but such indicators are not always unambiguous. The prognosis largely depends on a combination of many factors, not just resting body temperature.

The individual characteristics of the body should be taken into account. You can find out about them if you keep a BT chart for several months. Based on the indicators, it will become clear what is inherent in a particular female body at each phase and before menstruation. Also, you should not prematurely rejoice in pregnancy if BT is high before the onset of menstruation.

Various factors affect a woman's body. The seasonality of the year should be taken into account, which also affects the state of general health. After taking measurements for six months or a year, we can draw some conclusions. It is better to review the schedule with a gynecologist, who takes into account many factors. This will help either conceive a child or get rid of female problems that prevent you from getting pregnant.

The standard human body temperature is 36.6°C, but if you dig deeper, this is not exactly the same number. During the day it fluctuates, as energy exchange occurs in the body every minute. Some proteins, fats and carbohydrates break down, while others are formed. These processes are caused by the release of thermal energy, which is concentrated in the intercellular substance and body cells.

Most of these processes occur in the liver, so this organ is the hottest - 38°C. The temperature in the rectum and oral cavity varies from 37.3 to 37.6 ° C, and the skin at the same moment is much cooler: 36.6 in the axillary zone and approximately 28 ° C in the heel area.

Basal temperature demonstrates the amount of heating of the human body only by internal organs. Without taking into account the heat that muscles produce during the work of the lower, upper limbs and torso. Simply put, basal temperature is the body temperature recorded immediately after waking up only the brain, and not the entire body as a whole. You need to measure it immediately after sleep, lying in bed with your eyes still closed.

Basal temperature can be measured to:

Determine ovulation and favorable days for conceiving a child;
Determine the days on which you can not use protection during sex;
Diagnose pregnancy at an early stage;
Assess the woman's hormonal state.

Today this is the most effective, accessible and cheap method for determining hormonal imbalance and ovulation. It is not very suitable for early diagnosis of pregnancy, only if the woman has a healthy body and a stable menstrual cycle.

Basal body temperature is measured every morning at the same time (± 30 minutes), without getting out of bed and using a regular mercury thermometer;

Sleep before the measurement should last at least 4-6 hours;
The thermometer is inserted into the rectal opening (rectum), or can be inserted into the vagina or mouth. The most accurate readings will be if the thermometer is inserted into the rectal opening. In the oral cavity, the temperature is only 0.25-0.5°C higher than in the armpit. This method is used in the diagnosis of thyroid diseases;
Measurement time – 7-10 minutes. You cannot measure your temperature every day in different ways. If you decide to measure in the vagina, then throughout the entire time you need to measure only there. BT is not measured under the arm. You cannot change thermometers;
For the reliability of the indicators, it is advisable to give up smoking, drinking alcoholic beverages, and avoid stress. Inaccurate readings can be caused by insomnia, oral contraceptives, sleeping pills, various diseases (inflammations), frequent flights or moving, sexual intercourse several hours before waking up, overeating at night;
To prevent your efforts from being in vain, do not forget to put the broken thermometer next to the bed in the evening, so that you can easily reach it with your hand;
Indicators for 3-4 cycles of measurements are entered into a chart, which must then be presented to the doctor. The graph represents two coordinate axes: temperature and day of the month. A few days' worth of information is enough to determine pregnancy.

Basal temperature increases with each additional hour of sleep, so it should be measured at the same time and preferably before 8 am. During the day, the temperature of the body and internal organs of a person constantly changes and this is normal. It depends on physical activity, food intake, emotional stress experienced, clothing and other environmental factors.

Finding the optimal time for measurement during the day is almost impossible. If the biological activity of the body is moderate in the evening and morning, then during the day it can approach its maximum value.

BT in the evening is always higher than morning readings; measuring it at this time of day is not recommended. But if you are awake at night, you can measure BT during the day after sleeping for at least 5 hours.

The basal temperature recorded in the morning when you wake up may differ from the temperature in the evening by one degree. For medical analysis, this is quite a large discrepancy. It is the morning value that is the norm from which women and the doctors treating them are based.

You can start keeping a graph of basal temperature when planning pregnancy and finish monitoring after the first trimester. It provides relatively reliable information about the functioning of the ovaries and the state of the uterine epithelium. The functioning of these organs is controlled by the hormones progesterone and estrogen, periodically increasing and decreasing on certain days.

The “thermometer method” is often criticized: failure to follow the measurement rules leads to blurred results and confuses the woman during the analysis. Of course, a medical examination is much more reliable, but there is nothing wrong with independently monitoring your own health during pregnancy. There will be no harm from additional precautions unless mandatory medical support is avoided.

Due to evening loss of strength, basal temperature during pregnancy can drop by 0.1-0.2°C. The temperature during the day is not taken into account; depending on the varying degrees of activity of the body, it tends to decrease and increase every hour.

How does temperature change during a cycle?

The menstrual cycle consists of two phases. Basal temperature varies depending on the phase. In the first phase of the cycle, estrogen exerts its influence, and after ovulation (second phase), progesterone begins to act. During menstruation, the temperature is always elevated (37°C). At the end of menstruation it decreases to 36.2 - 36.7°C. Ovulation occurs with a jump to 36.9-37.2°C over three days, so it can be easily calculated and the date of release of the egg next month can be found out. The second phase of the cycle is caused by increased temperature, and a week before the next menstruation there is a decrease to the previous value - 36.2-36.7. If BT continues to remain at 37°, then the hormone progesterone has begun to prepare the uterus to receive a fertilized egg. This is the first sign of pregnancy before the delay.

However, it must be taken into account that in addition to pregnancy, increased BT at the end of the second phase can be caused by infectious gynecological diseases, physical activity and certain medications. The elevated rate persists throughout almost the entire pregnancy.

There is an opinion that before a miscarriage or fetal death, a decrease occurs. There is no need to take this information seriously. A one-time decrease may be associated with the general condition of the body or measurement error during pregnancy. But if there is a persistent decrease, then you can play it safe and consult a doctor. An increase to 37.8°C or higher can also be an alarming signal from the body about the occurrence of inflammatory processes during pregnancy.