Ovulation is a process that takes place in the body of a he althy woman, which is associated with the release of an egg into the fallopian tube for further fertilization. Knowing when you ovulate can help you plan your pregnancy or prevent unwanted conception. There are several methods for determining it, but the most accessible and simple is the measurement of basal body temperature.
What is this?
Basal body temperature (BBT) is an indicator that is measured in a state of complete rest, in the anus, immediately after waking up in the morning. It is a reflection of the hormonal background of a woman and allows you to identify problems in the work of the sex glands. However, more often BBT is used to determine the days favorable for conception.
Many gynecologists advise women to keep their own basal temperature chart. Especially for those who are planning to replenish the family. The schedule of basal temperature during ovulation has its own characteristics. It allows you to calculate the most suitable day forin order to get pregnant. Basal body temperature directly depends on the hormonal processes in a woman's body.
The menstrual cycle and its phases
The female body was created to procreate, so all the processes occurring in it are aimed at ensuring conception and preparing the body for pregnancy and childbirth. The menstrual cycle has three consecutive phases: follicular, ovulatory and luteal.
The first phase begins with menstrual bleeding, then there is the formation of a follicle in the ovary and the formation of a new endometrium. Its duration can suggest a graph of basal temperature. Its normal duration is 1-3 weeks. In this phase, the follicle-stimulating hormone and estrogen play a role. It ends with the maturation of the follicle.
The second phase is ovulation itself. The walls of the follicle rupture, and the egg passes through the fallopian tube towards the sperm. The phase lasts about 2 days. If fertilization occurs, then the embryo attaches to the endometrium, if not, the egg dies. On a normal chart, the basal temperature on the day of ovulation is at the lowest level of the entire cycle.
In the third phase, the production of progesterone begins. It is produced by the corpus luteum, which formed at the site of the ruptured follicle. The basal temperature after ovulation changes upwards - by 0.4-0.6 ° C. During this period, the female body prepares for bearing and preserving the fetus. If conception does not occur, then the concentration of female sex hormones decreases, and the circle closes,the follicular phase begins. Its normal duration in all women is about 2 weeks.
Why does temperature fluctuate?
Measurement of basal temperature during ovulation as a method characterizing hormonal changes in a woman's body was proposed in 1953 by the scientist Marshall. And now approved by WHO as an official method for detecting fertility. Its basis is a regular change in the concentration of progesterone in the blood. This hormone acts on the thermoregulatory center in the brain, which causes a local increase in temperature in the organs and tissues of the small pelvis. That is why a sharp increase in temperature in the anal region occurs in the luteal phase.
Thus, ovulation divides the menstrual cycle into two parts: in the first, the average temperature is approximately 36.6-36.8 °C. Then it goes down by 0.2-0.3 °C for 2 days, and then rises to 37-37.3 degrees and stays at this level almost until the end of the cycle. A normal basal temperature chart during ovulation is called biphasic.
Measurement of BBT can help to determine with high accuracy the day that is successful for conception. According to statistics, it is known that the highest probability of getting pregnant will fall on the day before and after the temperature rise - 30% each. 2 days before the jump - 21%, 2 days after - 15%. Pregnancy can occur with a 2% chance if fertilization occurs 3 or 4 days before the temperature rises.
What is this method used for
If you composeconstantly graph of basal temperature, the norm and pathology begins to be traced literally after 2-3 cycles. The resulting curves can answer many questions. Therefore, gynecologists strongly recommend this method to solve the following problems:
- Determination of an auspicious day for conception.
- Early detection of pregnancy.
- As a method of contraception.
- Detecting malfunctions in the sex glands.
Basal temperature is mainly measured to calculate the day of the beginning of the ovulatory phase of the cycle. This is the easiest and cheapest way. Determining ovulation by basal temperature is very easy if you measure regularly and follow all the rules.
Correct measurement is the key to the effectiveness of the method
In order for the results of the method to be true, it is necessary to follow all the instructions when measuring BBT, because it is very important that the basal temperature chart during ovulation includes only accurate and reliable data. There is a set of ground rules:
- Measurement of temperature is carried out daily at the same time (optimally - 7.00-7.30) in the rectum.
- Before the procedure, you must sleep at least 3 hours.
- If a woman had to get out of bed before the measurement time, then the readings must be taken before taking a vertical position.
- The thermometer must first be prepared and placed near the bed. Shake it off before bed.
- Measure the temperature only in a horizontal position, lying motionless on your side.
- Do not change during cyclethermometer.
- It is better to enter readings into the graph immediately after measurement.
Both digital and mercury thermometers are suitable for measurements. But an infrared thermometer is absolutely not intended for this method, since it has a high probability of an error in the results. Since the basal temperature before ovulation and on the day it starts differ by only 0.2-0.3 ° C, such a thermometer may not show this difference. An electronic thermometer gives large errors if you do not follow the instructions for its use. The most accurate measurements can be obtained using a mercury thermometer, however, it requires special care when handling.
When the received indicators may be incorrect
It must be remembered that the basal temperature during ovulation, the norm of which is individual for each woman, may fluctuate depending on the influence of various factors. Often, external influences on the body lead to the fact that BBT indicators are highly distorted and have no informative value. These factors include:
- Flights, transfers, business trips.
- Stress.
- Excessive alcohol intake.
- Taking psychotropic and hormonal drugs.
- Inflammatory processes in the body, fever.
- Increased physical activity.
- Short sleep.
- Not following measurement instructions.
- Intercourse a few hours before measurement.
If something from the above list happened, thenmeasurements are not to be trusted. And the day on which there was a violation can be ignored in the construction of the graph.
How to plot a basal temperature chart
To build a graph of basal temperature, you need to take measurements every day and make notes in a specially designated notebook. The graph is the intersection of two lines at a right angle. The vertical axis contains data on temperature, for example, from 35.7 to 37.3 ° C, and on the horizontal axis are the days of the menstrual cycle. Each cell corresponds to 0.1 °C and 1 day. After making the measurement, you need to find the day of the cycle on the graph, mentally draw a line up and put a dot in front of the desired temperature. At the end of the cycle, all points of the graph are connected, the resulting curve is an objective display of hormonal changes in the female body.
In the chart, you should indicate the current date and build a column for special notes. To make the data sufficiently complete, you can describe your state of he alth, the symptoms that appear, or situations that could be displayed on a change in basal temperature.
If a woman is not very clear on how to plot a basal temperature, then a gynecologist from the antenatal clinic will definitely explain how to do this, and also help decipher the data.
Now there are many programs with which you can create an electronic schedule that will always be at hand. In this case, the woman just needs to enter the temperature. The program will do the rest.
Graph transcript
In thismethod of determining fertility, it is important not only to build, but also to decipher the graphs of basal temperature. The norm for each woman is individual. However, there is an approximate view of the graph, which should be obtained if the gonads are working properly. To analyze the resulting curve, you need to build the following elements: overlapping line, ovulation line, duration of the second phase.
Overlapping (middle) line is built over 6 points of the follicular cycle without taking into account the first 5 days and days when the indicators deviated greatly due to external factors. This element has no meaning. But necessary for clarity.
Basal body temperature drops on the day of ovulation, so to determine the day for a successful conception, you need to find consecutive points that are under the overlapping line. At the same time, the temperature values of 2 out of 3 points should differ by at least 0.1 °C from the midline, and at least 1 of them should have a difference of 0.2 °C with it. The next day after that, you can observe a jump of the point up by 0.3-0.4 degrees. In this place, you need to draw an ovulation line. If there are difficulties with this method, then you can use the "finger" rule to plot. To do this, it is necessary to exclude all points that differ by 0.2 degrees from the previous or subsequent indicator. And based on the resulting schedule, build an ovulation line.
Basal temperature after ovulation in the anus should be kept at the markabove 37°C for 2 weeks. Deviations in the duration of the second phase or a small jump in temperature indicate ovarian dysfunction or low productivity of the corpus luteum. If 2 cycles in a row the duration of the second phase does not exceed 10 days, then it is necessary to consult a gynecologist, since this is the main sign of progesterone deficiency of the luteal phase.
The basal temperature chart during ovulation should also correspond to the norm for such a parameter as the temperature difference between the follicular and luteal phases. This indicator should be equal to more than 0.4 °С.
What does the graph look like in the presence of ovulation and pathologies
The normal ovulatory schedule has two phases. In the first one, an average temperature of 36.5-36.8 °C can be observed for 1-3 weeks, then a drop by 0.2-0.3 °C and a sharp rise to 37 °C and above. In this case, the second part of the schedule should be no shorter than 12-16 days, and before the onset of bleeding, there is a slight decrease in temperature. Graphically it looks like this:
You should also give examples of basal temperature graphs in which pathology can be traced. The curve in this case will differ from the norm in various ways. If there is an estrogen-progesterone deficiency, then the temperature jump will be no more than 0.2-0.3 ° C. This condition is fraught with infertility, therefore, it requires an appeal to specialists.
If the second phase on the chart is shorter than 10 days, then thisa clear sign of progesterone deficiency. Usually, there is no decrease in temperature before the onset of menstrual bleeding. In this case, pregnancy is possible, but at risk of termination.
If there is a lack of estrogen in a woman's body, then the schedule will be chaotic, strikingly different from the norm. It may also be due to the influence of external factors (flights, excessive alcohol intake, inflammation, etc.).
When the curve does not have sharp jumps in temperature and is a monotonous graph, then this is called an anovulatory cycle. This happens in he althy women, but not more than 1-2 times a year. If this is repeated from cycle to cycle, then this may be a sign of infertility.
If, after the second phase, there is no decrease in temperature, then most likely the woman is pregnant.
Deciphering the basal temperature charts, examples of which are presented above, require specialist knowledge. Therefore, you should not draw conclusions on your own, diagnose yourself and prescribe treatment.
Advantages and disadvantages of the method
The advantage of the method is its absolute availability, simplicity and total absence of costs. When the basal temperature chart during ovulation is maintained by a woman regularly, this makes it possible to determine the days of ovulation, recognize early pregnancy in time, or detect hormonaldeviations and consult a gynecologist.
However, there are also disadvantages in the method. This method is not very accurate due to the individual characteristics of each organism. Here are its main disadvantages:
- Does not predict when the ovulatory phase will come.
- Does not give accurate information about when you ovulated.
- Does not guarantee, even with a normal biphasic schedule, that ovulation actually took place.
- Cannot give specific information about the amount of progesterone in the blood.
- Does not provide data on the normal functioning of the corpus luteum.
To know exactly how informative the method is, it is necessary in the first couple of cycles to take blood tests for female hormones and do an ultrasound scan. If the data of the graph and research coincide, then the woman can easily keep a graph of basal temperature. The norm and deviations displayed on the curve, in this case, will correspond to reality.
This method is convenient, simple and does not require financial expenses. If you follow all the rules exactly and know how to decipher the basal temperature chart, then finding out the day of ovulation and planning conception is very easy. However, if there are any deviations from the norm, it is worth contacting a specialist to prevent the development of pathological processes.
