Medical expert of the article
New publications
Basal temperature at approach of pregnancy: schedules in the morning and in the evening, norms or rates
Last reviewed: 19.10.2021
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
Almost every woman knows about the existence of basal temperature. However, not everyone understands what exactly is talking about, and for what reasons the basal temperature during pregnancy is so variable. Let's try to explain in detail and answer the main questions that are related to this concept.
Basal temperature is considered a value, which to some extent reflects the woman's gynecological status. This indicator is often used in the period of pregnancy planning, based on the schedule of variability. For example, on a similar graphical outline, you can "calculate" the day in which ovulation occurs - these are the most successful 24 hours for conception of the baby. The basal temperature is variable: its oscillations are observed before and after the ovulation moment, during implantation, or when conception did not take place. Only in the absence of ovulation, BT values remain unchanged.
Where is the 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 indicators:
- BT is measured at the same hour - for example, exactly at seven o'clock in the morning every day;
- The measurements should be preceded by a long dormant state, so it is preferable to determine the BT after a night rest.
What does the measurement give? First of all, the basal temperature shows changes in the hormonal balance. Such changes - for physiological reasons - have only local localization, so attempts to determine such temperature in other places (in the mouth, under the mouse) will not succeed.
Before assessing the basal temperature, one should also take into account this point: any cold or even fatigue can affect the final figures. Therefore, in such states, exponential numbers can not be interpreted correctly.
What should be the basal temperature during pregnancy?
- During pregnancy, the adequate basal temperature can not fall by more than 0.2 °. Optimal values are within the limits of 37-37.3 °, or more.
- Sharp fluctuations in the values in the form of ups and downs - this is the reason for a quick appeal to the gynecologist.
- The figures reflecting the basal temperature are directly dependent on the hormonal female background. This background can be "corrected" medically. If you do not take measures in a timely manner, it is possible to interrupt pregnancy, or other violations.
- In some women, indicators can reach even 38 ° C, which depends on the individual characteristics. This state is also considered a variant of the norm.
Basal temperature during pregnancy
The concept of the norm is relatively relative. However, it is considered that the basal temperature during pregnancy, when pregnancy occurs, in the early stages varies in the approximate range from 37 ° to 37.3 ° C. However, these figures are able to vary, depending on various reasons. For example, a significant effect on the indicators has a hormonal level - first of all, the degree of progesterone production.
Also, the increase in values can be observed:
- - with inflammatory processes;
- - for banal incorrect measurements;
- - with other gynecological pathologies (non-inflammatory etiology);
- - with physical fatigue;
- - if on the eve of the measurement there was sexual contact;
- - against the background of the use of various medications (for example, hormonal drugs).
The permissible maximum basal temperature is a figure of 38 ° C. A larger indicator should be the reason for an uncomplicated medical consultation - probably, there is a hidden inflammatory reaction in the body that can harm the course of pregnancy.
What is the basal temperature during pregnancy in the morning, in the evening?
The basal temperature is estimated only in the morning - after a good night's rest. Removal of measurements in the evening is possible only when a woman sleeps during the day at a minimum of five hours. In other options, the evening indicators will not correspond to reality, as they will be distorted and only confuse the maintenance schedule.
Baseline temperature measurement during pregnancy
If you measure basal temperature one-time, then the information obtained will not be enough to make any conclusions. The base is considered to be an indicative aggregate - that is, it is necessary to collect data regularly, during a certain time period.
And one more nuance that many do not take into account: if a woman takes hormonal preparations, then the information on basal temperature can be erroneous. This is because cyclical processes in such a situation are "built" on the hormonal medications taken, and only to a lesser extent - on their own hormones.
Basal temperature is determined in the morning, until the moment when a woman gets out of bed. It's best to set the alarm for a certain time (you need it to be at hand, and you do not have to get up to turn it off). Also in the accessibility zone there should be a thermometer and a pencil - in order to record the received figure.
Before the measurements, you should not break the resting state of the body - you can not stretch, get out from under the blanket, and even more so - sit on the bed. The only permissible movement is an easy adjustment of the legs in the knees for a comfortable introduction of the thermometer (inside the vagina or in the rectum). Then you should lie down for at least five minutes without moving. After 5-6 minutes, the thermometer must be removed and placed on a clean cloth. The indicators can be recorded immediately, but you can do it later - for example, if the woman decided to have another nap.
Only measurements made in the manner indicated above are considered informative. Many carry out 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 vice versa - will add chaos to the indicative schedule.
[Basal temperature in pregnancy planning
Pregnancy planning is a responsible step, and many women try to follow all the processes as carefully as possible in order for conception to be successful.
In the planning period, the basal temperature is measured inside the rectum, daily, preferably from six to eight in the morning, before getting out of bed.
The information received during the waking period is not taken into account, even if before the measurement the woman did not sleep for about half an hour. Before taking measurements, you should not toss in the bed, stretch, rise, as such actions contribute to the flow of blood to the small pelvis, which significantly affects the indicators.
Do not measure the temperature if there were stressful or physical exertions before bed, there was a feast with alcoholic drinks, or insomnia was disturbed during the night.
All the received figures are entered every morning in the notebook: it is necessary to designate the day of the monthly cycle and the temperature index.
It is known that the monthly cycle is divided into I and II phases. I phase is the period beginning with the appearance of drops of blood, and ending 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 the onset of pregnancy is adequate duration of phase II (i.e., no less than 10-14 days). If the II phase is short, it is important to consult a medical specialist and pass tests to assess the hormonal background.
The basal temperature during the I phase is held within the boundaries of 36.3-36.6, and in the subsequent phase it rises to the numbers from 36.8 to 37.1.
Specialists point out at such a time: the difference between the indices between phases I and II should not be less than 0.3-0.4 °, otherwise we can speak about any disorders.
The basal temperature during pregnancy before the delay in the II phase should gradually increase or sharply increase. Most often, the basal temperature after ovulation rises gradually over the course of three days.
Optimal for successful planning to enter into sexual intercourse 1-2 days before ovulation, directly on the day of ovulation, or the next day after it.
When does basal temperature during pregnancy?
If the pregnancy is confirmed, but the graphical curve of the basal temperature is displayed chaotically, this can happen only for several reasons:
- - The temperature is measured incorrectly, with disturbances (for example, not at the same time, after a while after awakening, etc.);
- - the hormonal background is broken in the body (in this case it is necessary to pass an analysis for the content of hormones at a certain time);
- - There are inflammatory diseases.
To clarify the situation, it is better to consult a doctor: you may need additional diagnostics. Independently make any decisions ahead of time and worry for no reason is not, because the state of a woman is reflected and the state of her future baby.
Basal temperature chart for pregnancy, weekly
The basal temperature of 36.9-37 during pregnancy is more likely to correspond to the initial week, but the figures may differ depending on the individual characteristics of the future mother. As a rule, the indicators gradually increase, but do not exceed 38 ° C.
Some women in the second week the temperature drops a little - not critical, which also corresponds to the norm. Such a condition is called implantation, and after 1-2 days the indicators rise again.
In the third week, the basal temperature is usually within 37 ° (can rise to 37.7 ° or slightly more). If the indicator is less - then it is worth consulting with the doctor. It is possible that you will have to pass the analysis and continue to take hormonal drugs.
The fourth week is a period of consistently high rates. Thus, basal temperature 38 during pregnancy, or slightly lower, is considered optimally acceptable. But higher figures are an excuse for medical advice (perhaps there is an infection or an inflammatory reaction).
The fifth and sixth week - the basal temperature continues to hold on high figures (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 measuring BT, you should pay attention to other sensations - for example, on soreness, sipping muscles, etc.
The basal temperature of 36 in pregnancy is too low, which is often associated with the present threat of miscarriage. However, one can not say 100% of the threat, we need to get an additional consultation with an obstetrician-gynecologist.
It is believed that such a threat of interruption exists up to 12 weeks, and during this entire period the basal temperature should be kept within the limits from 37.1 ° to 37.8-38 °, but not higher.
After 12 weeks, the measurement of the indicators loses its usefulness, since the basal temperature at this stage is normalized.
Basal temperature with a stiffened pregnancy
In a number of situations, a decrease in the basal temperature at the initial stage of gestation may indicate a fading in fetal development. Why it happens, it is difficult to say: there can be quite a lot of reasons.
Pregnancy fading is characterized by a drop in basal temperature below 37 ° C. The fetus stops its development, the yellow body does not function (in particular, the production of progesterone stops).
If the figures on the thermometer show less than necessary, then do not experience it in advance. It is necessary to conduct additional diagnostics. In addition to the basal temperature, when the fetus fades, the entire pregnancy process stops: the hCG decreases, and the test again shows one strip.
Basal temperature during IVF of pregnancy
When the patient becomes pregnant as a result of in vitro fertilization, support is given to her as soon as possible, immediately after the embryo has been transferred to the uterus. Observation of such a woman is always more thorough: in almost all cases, high doses of hormonal drugs are prescribed to her.
If the pregnancy was realized after the IVF procedure, the hormonal balance in the body changes, as in a standard pregnancy. For this reason, the graphical curve that reflects the basal temperature will look exactly the same. Sometimes the use of high doses of hormonal drugs can also affect the construction of the curve, so only the basal temperature is not considered as a sufficiently informative procedure.
After extracorporeal fertilization, it is necessary to observe the development of the fetus especially closely. And basal temperature - this is only part of the information that must be traced during the entire gestation period.
Increase and decrease in basal temperature during pregnancy, causes
Discussing the norm in information on basal temperature is only conditional: it is meaningless to expect that within the body the indicators will be reflected exclusively on a clear schedule. It should also take into account the individual characteristics of the woman, which in no small measure affect the movement of temperature values up or down. For example, it often happens that with an adequately ongoing pregnancy, BT values deviate from the numbers indicated in the textbook. Experiencing does not follow: in most situations this does not affect the possibility of bearing and the birth of a healthy baby.
As specialists explain, the definition of basal temperature numbers is informative only during the first trimester. In subsequent periods, these values do not play a decisive role. But also at the initial terms they should not be overestimated. Basal temperature is usually considered in combination with other manifestations and symptoms, so worry if the numbers on the thermometer do not coincide with the expected, should not be. It is better to apply to a competent gynecologist who will conduct an examination and assess the condition of the pregnant woman as a whole.
Why is the doctor's consultation so necessary? Sometimes low basal temperature after ovulation during pregnancy indirectly indicates the existing threat of spontaneous miscarriage. The main reason for this phenomenon is the inadequate production of progesterone by the body. An important hormone for pregnant women - progesterone - is responsible for providing conditions in which a fetal egg will develop: this is the friability of the endometrium, and the strengthening of the embryo in this layer.
Progesterone causes an increase in basal temperature numbers directly. For example, basal temperature in the second phase during pregnancy - that is, during the first couple of weeks from the moment of ovulation - is already held within 37 ° C. If the indicators are less - then either the pregnancy has not taken place, or there is a high probability of its early interruption. Especially you should be concerned if, against a background of low basal temperature and a positive test response to pregnancy, a woman feels painful sipes in the abdomen and / or spotting.
We draw attention to this nuance: the baseline temperature measurements and the scrupulous outline of the graphic curve can not 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 the doctor can either exclude or confirm suspicions.