Basal temperature at the onset of pregnancy: graphs in the morning and evening, norms

Almost every woman knows about the existence of basal temperature. However, not everyone understands what exactly we are talking about and why basal temperature during pregnancy is so variable. Let's try to explain in detail and answer the main questions related to this concept.

Basal temperature is considered a value that to a certain extent reflects the gynecological condition of a woman. This indicator is often used in the period of pregnancy planning, based on the variability graph. For example, using such a graphic drawing, you can “calculate” the day on which ovulation will occur - this is the most favorable 24 hours for conceiving a baby. Basal temperature is changeable: its fluctuations are observed before and after the ovulation moment, during implantation or when conception has not occurred. Only in the absence of ovulation do BT indicators remain unchanged.

Where is basal temperature measured during pregnancy?

The temperature, called basal, is calculated per rectum - inside the rectal or vaginal cavity. It is not enough to simply determine the rectal or vaginal temperature: there are several conditions for obtaining correct readings:

• BT is measured at the same time - for example, exactly at seven o'clock in the morning every day;
• Measurements should be preceded by a long period of rest, so it is preferable to determine BT after a night's rest.

What does the measurement give? First of all, the basal temperature demonstrates changes in the hormonal balance. Such changes - for physiological reasons - have only local localization, so attempts to determine such a temperature in other places (in the mouth, under the arm) will not be successful.

Before assessing the basal temperature, one should also take into account the following: any cold or even fatigue can affect the final figures. Therefore, in such conditions, the indicative figures can be interpreted incorrectly.

What should be the basal temperature during pregnancy?

• During pregnancy, adequate basal temperature cannot fall by more than 0.2°. Optimal values are within the range of 37 – 37.3°, or more.
• Sharp fluctuations in values in the form of ups and downs are a reason to quickly contact a gynecologist.
• The numbers reflecting the basal temperature are directly dependent on the female hormonal background. This background can be "corrected" with medication. If measures are not taken in a timely manner, then a miscarriage or other disorders are possible.
• In some women, the readings can reach even 38°C, depending on individual characteristics. This condition is also considered a normal variant.

Normal basal temperature during pregnancy

The concept of the norm is quite relative. However, it is generally accepted that the basal temperature during pregnancy, when pregnancy occurs, in the early stages fluctuates within the approximate range from 37° to 37.3°C. However, these figures can change, depending on various reasons. For example, the hormonal level has a significant impact on the indicators - first of all, the degree of progesterone production.

Also, an increase in values can be observed:

• - in inflammatory processes;
• - in case of banal incorrectly carried out measurements;
• - in other gynecological pathologies (non-inflammatory etiology);
• - in case of physical fatigue;
• - if there was sexual contact the day before the measurement;
• - against the background of the use of various medications (for example, hormonal agents).

The acceptable maximum basal temperature is 38°C. A higher value should be a reason for an immediate medical consultation - there is probably a hidden inflammatory reaction in the body that can harm the course of pregnancy.

What is the basal temperature during pregnancy in the morning and evening?

Basal temperature numbers are assessed only in the morning – after a good night's rest. Taking measurements in the evening is only possible when a woman sleeps during the day for at least five hours. In other cases, the evening readings will not correspond to reality, as they will be distorted and will only confuse the chart.

Basal temperature measurement during pregnancy

If you measure your basal temperature once, the information you get will not be enough to draw any conclusions. The base is considered to be an indicative set - that is, it is necessary to collect data regularly, over a certain period of time.

And one more nuance that many do not take into account: if a woman takes hormonal drugs, then the information on basal temperature may be erroneous. This happens because cyclic processes in such a situation are “built” on the hormonal drugs taken, and only to a lesser extent - on one’s own hormones.

Basal temperature is determined in the morning, before the woman gets out of bed. It is best to set an alarm clock for a certain time (it should be at hand, so that you do not have to get up to turn it off). Also, a thermometer and a pencil should be within reach - in order to write down the resulting figure.

Before taking measurements, do not disturb the resting state of the body - do not stretch, get out from under the blanket, and especially - sit on the bed. The only permissible movement is a slight adduction of the legs at the knees for comfortable insertion of the thermometer (into the vagina or into the rectum). Then you should lie still for at least five minutes. After 5-6 minutes, the thermometer must be removed and placed on a clean napkin. The readings can be written down immediately, but this can also be done later - for example, if the woman decides to sleep some more.

Only measurements taken in the manner described above are considered informative. Many perform the procedure several times a day, or every couple of hours. But such manipulations will not clarify the picture of the true state of the female body, and even on the contrary - they will add chaos to the indicative graph.

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Basal temperature when planning pregnancy

Planning a pregnancy is a responsible step, and many women try to monitor all processes as carefully as possible to ensure successful conception.

During the planning period, the basal temperature is measured inside the rectum, daily, preferably from six to eight in the morning, until the moment of getting out of bed.

Information obtained during the waking period is not taken into account, even if the woman has not slept for about half an hour before the measurement. Before taking measurements, you should not toss and turn in bed, stretch, or lift yourself up, as such actions contribute to the flow of blood to the pelvis, which significantly affects the indicators.

You should not measure your temperature if you were stressed or physically active before going to bed, had a party with alcoholic drinks, or had insomnia during the night.

All the numbers obtained are recorded in a notebook every morning: it is necessary to indicate the day of the monthly cycle and the temperature reading.

It is known that the monthly cycle is divided into phases I and II. Phase I is the period that begins with the appearance of drops of blood and ends with the onset of ovulation. Phase II begins on the second day after ovulation and continues until the beginning of the next monthly cycle.

An important condition for pregnancy is an adequate duration of phase II (i.e., not less than 10-14 days). If phase II is short, it is important to consult a medical specialist and take tests to assess hormonal levels.

During the first phase, the basal temperature is maintained within the range of 36.3-36.6, and in the subsequent phase it increases to numbers from 36.8 to 37.1.

Experts also point out the following point: the difference in indicators between phases I and II should be no less than 0.3-0.4°, otherwise we may be talking about some kind of disorder.

Basal temperature during pregnancy before a delay in phase II should increase gradually or sharply. Most often, basal temperature after ovulation rises gradually, over three days.

For successful planning, it is optimal to have sexual intercourse 1-2 days before ovulation, directly on the day of ovulation, or the next day after it.

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When does basal temperature fluctuate during pregnancy?

If pregnancy is confirmed, but the basal temperature curve is displayed chaotically, then this can only happen for several reasons:

• - the temperature is measured incorrectly, with irregularities (for example, at different times, some time after waking up, etc.);
• - the hormonal balance in the body is disturbed (in this case, it is necessary to take a test for hormone levels at a certain time);
• - there are inflammatory diseases.

To clarify the situation, it is better to consult a doctor: additional diagnostics may be needed. You should not make any decisions on your own ahead of time or worry without reason, because the woman's condition is reflected in the condition of her future baby.

Basal temperature chart during pregnancy, by week

Basal temperature of 36.9-37 during pregnancy usually corresponds to the first week, however, the figures may differ depending on the individual special characteristics of the expectant mother. As a rule, the indicators gradually increase, but do not exceed 38°C.

Some women experience a slight temperature drop in the second week – not critical, which is also normal. This condition is called implantation dip, and after 1-2 days the readings rise again.

In the third week, the basal temperature is usually within 37° (it can rise to 37.7° or a little more). If the indicator is lower, then you should consult a doctor. It is possible that you will have to take a test and take hormonal drugs in the future.

The fourth week is a period of consistently high indicators. Thus, a basal temperature of 38 during pregnancy, or slightly lower, is considered optimally acceptable. But higher numbers are a reason for a doctor's consultation (there may be an infection or inflammatory reaction).

Fifth and sixth weeks – the basal temperature continues to remain at high levels (not less than 37.1° and not more than 38°). This level is considered optimal during the first sixteen weeks after fertilization. In addition to BT measurements, you should also pay attention to other sensations – for example, pain, muscle tension, etc.

Basal temperature of 36 during pregnancy is too low an indicator, which is often associated with the existing threat of miscarriage. However, it is impossible to say with absolute certainty about the threat; you need to additionally consult an obstetrician-gynecologist.

It is believed that such a threat of interruption exists up to the 12th week, and during this entire period, the basal temperature should be maintained within the range of 37.1° to 37.8-38°, but not higher.

After 12 weeks, measuring the indicators loses its usefulness, since the basal temperature at this stage normalizes.

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Basal temperature in case of frozen pregnancy

In some situations, a decrease in basal temperature at the initial stage of gestation may indicate a cessation of fetal development. It is difficult to say why this happens: there can be quite a few reasons.

A frozen pregnancy is characterized by a drop in basal temperature below 37°C. The fetus stops developing, the corpus luteum does not function (in particular, progesterone production stops).

If the numbers on the thermometer show less than necessary, then you should not worry in advance. You need to conduct additional diagnostics. In addition to the basal temperature, when the fetus stops, the entire pregnancy process stops completely: hCG decreases, and the test again shows one strip.

Basal temperature during IVF pregnancy

When a patient becomes pregnant as a result of in vitro fertilization, support is provided to her from the earliest possible stage – immediately after the embryo is transferred to the uterus. Monitoring of such a woman is always more thorough: in almost all cases, she is prescribed high doses of hormonal drugs.

If pregnancy occurs after IVF, the hormonal balance in the body changes as in a standard pregnancy. For this reason, the graphical curve reflecting the basal temperature will look exactly the same. Sometimes taking high doses of hormonal agents can also affect the construction of the curve, so the basal temperature alone is not considered a sufficiently informative procedure.

After in vitro fertilization, it is necessary to monitor the development of the fetus especially carefully. And basal temperature is only part of the information that must be monitored throughout the entire period of gestation.

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Increase and decrease of basal temperature during pregnancy, reasons

Discussing the norm in the information on basal temperature is only conditional: it is pointless to expect that the indicators inside the body will be reflected exclusively according to a clear schedule. It is also necessary to take into account the individual special characteristics of the woman, which to a large extent affect the movement of temperature values up or down. For example, it often happens that with an adequately proceeding pregnancy, BT indicators deviate from the figures indicated in the textbook. There is no need to worry: in most situations, this does not affect the possibility of bearing and giving birth to a healthy baby.

As experts explain, determining the basal temperature numbers is informative only during the first trimester. In subsequent periods, these values do not play a decisive role. But they should not be overestimated in the initial stages either. Basal temperature is usually considered in combination with other manifestations and signs, so there is no need to worry if the numbers on the thermometer do not match the expected ones. It is better to consult a competent gynecologist who will conduct an examination and assess the condition of the pregnant woman as a whole.

Why is a doctor's consultation so necessary? Sometimes a low basal temperature after ovulation during pregnancy indirectly indicates an existing threat of spontaneous miscarriage. The main reason for this phenomenon is insufficient production of progesterone by the body. An important hormone for pregnant women - progesterone - is responsible for providing conditions in which the fertilized egg will develop: this is both the looseness of the endometrium and the strengthening of the embryo in this layer.

Progesterone directly causes an increase in basal temperature numbers. For example, the basal temperature in the second phase of pregnancy - that is, during the first couple of weeks from the moment of ovulation - is already maintained within the limits of 37°C. If the numbers are lower, it means either the pregnancy did not take place, or there is a high probability of its early termination. You should be especially concerned if, against the background of a low basal temperature and a positive test result for pregnancy, a woman feels painful pulling in the abdomen and/or bloody discharge.

We would also like to draw your attention to the following nuance: basal temperature measurements and meticulous drawing of a graphic curve cannot be considered a reliable diagnostic criterion. Any gynecologist will confirm: basal temperature during pregnancy is always considered taking into account other symptoms and signs. Only on the basis of the overall picture can the doctor either exclude or confirm suspicions.