Most women have heard about the concept of “basal temperature” more than once, but few understand what this medical term means, why this indicator needs to be controlled, and how to decipher the BT schedule of a pregnant and non-pregnant woman. We will help you figure it out.
Basal temperature - what is it?
Basal body temperature is the minimum indicator that is observed after prolonged sleep and rest. Various processes in a woman’s body increase BT indicators, it is thanks to this feature that it is possible to determine changes in the hormonal background during the menstrual cycle. Deviations in the indicators are a signal of certain violations in the operation of systems and organs. For example, pregnant women are often monitored. Schedules of BT with a low temperature in phase 2 may indicate a risk of miscarriage. And such indicators in a non-pregnant woman indicate infertility.
Why is basal temperature determined?
Analyzing changes in BT, the following pathologies are determined:
- The presence or absence of ovulation.
- Fertile days. The information obtained can be used both for pregnancy planning and for the calendar method of contraception.
- Cycle violations. In case of deviation from the norm, the doctor may suspect some diseases of the reproductive system, for example, the presence of an inflammatory process or insufficiency of the luteinizing phase, as well as hormonal disorders.
- With the help of BT indicators, you can find out about early pregnancy. The schedule of BT pregnant has its own characteristics, which are described in more detail below.
How to measure BT?
How to measure basal body temperature? To do this, stock up on a separate thermometer, preferably mercury. BT is measured in the mouth, vaginally and rectally. The latter method is considered the most preferable, since the results of such measurements are most reliable due to the minimal influence of external factors. BT is not measured in the armpit. You need to choose only one method, without changing it throughout the entire diagnostic period, which is at least 3 months. Measurements should be taken in the morning, after at least 6 hours of sleep, without getting out of bed, preferably at the same time.
Watch for changes in the basal temperature of a woman with a menstrual cycle, pregnant. BT schedules for planning girls will become indispensable assistants in determining the favorable days of conception of a child.
It is necessary to start recording BT indices on the first day of menstruation (the beginning of the cycle) in order to obtain complete information for a month period. Women who are pregnant should have BT schedules regularly throughout their first trimester.
It is recommended to record the results immediately after the measurement, since an error can affect the diagnosis and interpretation of indicators. In addition to indicating directly the temperature itself, it is necessary to indicate the day of the cycle, the number of days of menstruation. It is extremely important to note additional factors that may affect the measurement results: medication, lack of sleep, illness, stress, physical activity, sexual intercourse on the eve of the measurements, the use of spicy foods and alcohol. The schedule of BT for a pregnant woman, in addition to the above factors, should reflect the well-being and feelings of the woman.
Maintain BT records
You can write data in a notebook, but it is more convenient to use online applications or computer programs for recording and analyzing measurements of basal body temperature. Such a virtual assistant decrypts the BT schedule of a pregnant and non-pregnant woman: determines ovulation, calculates the average temperature of each phase of the cycle, identifies deviations from the norm, and gives recommendations. But do not forget that the resulting software decryption is only preliminary generalized data that cannot be a diagnosis and a guide to self-treatment. The recorded results must be shown to the attending gynecologist. Particular attention should be paid to the results obtained by pregnant women. Schedules of BT with a low temperature should be shown to your doctor.
Change in BT during the menstrual cycle
In order to understand the principle on which the diagnostic method using basal temperature is based, it is important to understand what processes in the woman’s body are associated with changes in temperature indicators.
The monthly menstrual cycle in medicine is usually divided into 4 phases:
- Menstrual - begins on the first day of menstrual flow. This day is also considered the first day of a woman’s monthly cycle. During this period, the body rejects the endometrium and prepares at the hormonal level for the development of a new egg. This phase lasts up to 7 days. BT in this period should normally correspond to 36.2–36.6 degrees.
- Then follows the follicular phase. During this period, the follicle-stimulating hormone is intensively produced in the body , which contributes to the development of follicles, and subsequently, the eggs. This period of the menstrual cycle lasts up to two weeks. The basal temperature in the follicular phase rises slightly and is normally 36.7–36.9 degrees. In a day or two, a pre-ovulatory temperature drop occurs - up to 36.3 degrees.
- The ovulatory phase lasts about 3 days. This period is characterized by a decrease in the production of follicle-stimulating and an increase in the level of luteinizing hormone. Thanks to the latter, the egg is released from the follicle - this process is called ovulation. This is the most favorable time for conceiving a baby. The basal temperature during ovulation rises and reaches indicators up to 37.7-37.9 degrees.
- The last phase, luteinizing, is characterized by intensive production of progesterone to maintain pregnancy in the event of its onset. The basal temperature in this phase remains above 37 degrees. In the absence of ovum fertilization, temperature indices drop sharply 1–2 days before the expected menstruation and amount to 36.6–36.8 degrees. After this, a new cycle begins.
The schedule of BT of a pregnant woman (after conception) should normally be in the form of a monotonic straight line with BT indicators above 37 ° C.
BT indicators
With basal temperature indices that correspond to the established norms, at the end of the monthly cycle, the curve of the resulting graph will have a clearly pronounced two-phase separation. So, in the first half of the cycle, the line will go below 36.8. A few days before ovulation, a pre-ovulatory decrease in temperature will be noted, after which there will be a sharp increase in indicators by at least 0.4 degrees. The jump is divided by the red line - this is the day of ovulation. After this, the elevated temperature lasts up to 14 days, then a premenstrual drop in the indicator is recorded.
BT during pregnancy: normal
If within 16 days after ovulation, the thermometer shows more than 37 degrees, this may indicate pregnancy. In case of conception, the egg is attached to the wall of the uterus. Progesterone and the "pregnancy hormone" - hCG - begin to be produced. When women are pregnant, BT graphs show a temperature of 37-37.6 o C. In 25% of cases in the early stages of embryo development, an increase of up to 38 o is observed. In addition, with normal progesterone production, there will be no premenstrual decline in basal temperature.
When confirming conception, doctors recommend that you continue to maintain the schedule throughout the first trimester. It is especially important to keep a schedule of BT for a pregnant woman who had a history of miscarriage or fading of the embryo. At a later date, such a procedure is uninformative due to changes in hormonal levels.
On sites for expectant mothers, forums, you can view the so-called "pregnant" BT schedules. A photo showing normal values during the menstrual cycle, accompanied by conception, is presented below.
Implantation retraction - what is it?
Often there are "pregnant" schedules of BT with implantation retardation - a sharp decrease in temperature approximately 5-7 days after ovulation. The next day, indicators return to a level above 37 degrees. This temperature change is observed during the period when the fertilized egg is attached to the uterine wall. Fixation of implantation depressions on the graph is considered a sign of pregnancy. In addition to a sharp jump in temperature, sometimes minor spotting from the genitals and pulling sensations in the lower abdomen can be observed. But if, at the same time as such symptoms, a woman observes “pregnant” charts with low BT, this is a serious reason for urgent seeking medical help - a risk of miscarriage is possible.
BT during pregnancy: deviations
Deviations from the established norms of basal temperature indicators often indicate various violations, sometimes dangerous conditions of a pregnant woman and a baby. If you comply with all the rules of measurement, and the thermometer records readings below 37 or above 38 degrees, urgent consultation of a specialist is necessary. It is necessary to pay attention to the state of health in the following situations:
- In previous cycles, the basal temperature in the post-ovulation period was 37–37.3 ° C, and during pregnancy it jumped sharply to 38. Such a change in indicators may indicate the presence of various kinds of inflammatory processes in the body. A number of tests and diagnostic procedures are required to make the correct diagnosis. But if, even before pregnancy, the temperature in the second half of the cycle was close to 38, there is no reason for concern, in which case high BT indices are individual characteristics of the body.
- “Pregnant” schedules of BT with a low temperature in phase 2 require urgent medical attention. Indicators below 37 degrees indicate a lack of progesterone - this is extremely dangerous during pregnancy. A decrease in hormone levels can threaten spontaneous abortion (miscarriage). With timely diagnosis of a pathological condition, it is possible to normalize progesterone levels by taking synthetic drugs. In this case, the probability of maintaining and further normal development of pregnancy is high. Another reason for the decrease in temperature may be a frozen pregnancy. Unfortunately, in this case, it is not possible to save the fetus. Such a diagnosis must be confirmed using ultrasound diagnostics. If pregnancy fading is confirmed, the doctor will prescribe curettage of the uterine cavity for medical reasons.
Basal temperature norm and deviations
The fact that the BT indices should normally be in a certain period of the menstrual cycle, we examined above. Now let's look at what types of graphs are indicative of deviations in the state of health:
- If in the second half of the cycle the basal temperature rises only slightly (up to 0.3 degrees) and such curves are recorded for several cycles in a row, the doctor may suspect a hormonal disorder: there may be a lack of progesterone. Such deviations lead to the absence of ovulation, and therefore to infertility.
- In most cases, women who have a baby who have a basal temperature rises only a few days before menstruation, and the duration of the second half of the cycle is 10 days or less, encounter problems. In addition, there is no decrease in temperature before the onset of menstruation. In this situation, doctors talk about the insufficiency of the second phase of the cycle, the threat of pregnancy failure. Timely detection of pathology is corrected with medications.
- The curve of the graph, which does not have a marked decrease and increase in temperature, and according to the results of the indicators it is not possible to divide the cycle into separate phases, indicates the absence of ovulation. Such a cycle is called anovulatory. During the year, normally a woman can have 1 cycle without ovulation. But if such a schedule is fixed for three months or more, you need to contact a gynecologist for an examination. With such indicators of basal temperature, pregnancy is impossible. An example of such a graph is graphically presented below.
- A zigzag, chaotic curve of the basal temperature graph indicates a lack of estrogen in the body of a woman. This leads to a lack of development of follicles, and subsequently the egg. And as a result - anovulation and infertility. Be sure to consult a specialist when fixing these types of schedules for longer than three cycles in a row.
Measurement of basal temperature is an effective and affordable home method for diagnosing various pathologies in a woman's body. The schedule of BT for a pregnant woman is extremely important - timely identification of a problem can save the life of a future baby and mother. But do not self-medicate - if the temperature indicators deviate from the norm, consult a gynecologist for advice.