Ovulation is a key event in a woman’s menstrual cycle. If you accurately determine the day when it occurs, it is possible not only to plan for conception, but also slightly affect the sex of the future baby.
Information on when an egg leaves the ovary can be obtained using various methods: ultrasound of the ovaries or determining the concentration of sex hormones during a cycle several times. But the simplest and free method that every woman is able to carry out at home has been and remains conducting basal thermometry. A careful analysis of how the basal temperature changes daily will provide an opportunity to study the work of the ovaries, to understand whether ovulation occurs or not, to determine the pregnancy before the test can show it.
The essence of the method of basal thermometry
A key role in the management of the female body is played by the sex hormones: progesterone and estrogen, prolactin, gonadotropic hormones of the hypothalamus and pituitary gland. The balance between them is reflected in a variety of processes, including body temperature, which is called basal.
The basal temperature is the lowest temperature indicator, indicating the actual temperature of the internal organs. It is determined immediately after rest (usually after a night’s sleep), before the start of any physical activity that will create measurement error. Only departments with a message to the body cavities are suitable for its establishment. It is the vagina (it is connected with the uterus), the rectum (it is directly connected with the thick sections of the intestine) and the oral cavity, which passes into the oropharynx.
Set the level of the basal hormone estrogen and progesterone. They dictate what the basal temperature should be in one or another woman with ovulation.
The normal amount of estrogen does not in itself affect the temperature index. The task of this hormone is to prevent progesterone from affecting the thermoregulatory center located in the hypothalamus (this is the area associated with the brain).
In the first half of the cycle, estrogen dominates. It does not allow the basal temperature to rise above 37 ° C. During the period of ovulation, when an increased amount of estrogen enters the bloodstream at the beginning, there is a decrease in the temperature index of about 0.3 ° C. When the egg leaves the follicle and a yellow body appears in its place, producing progesterone, the thermometer shows 37 ° C or more. At the same time, the schedule of basal thermometry becomes like a bird with wings wide open, whose beak symbolizes the day of ovulation.
Further, when the corpus luteum dies (if conception did not occur) and the amount of progesterone decreases, the temperature drops. During menstruation, the indicator is kept at 37 ° C, then decreases and everything repeats from the beginning.
If pregnancy occurs, progesterone is produced normally more and more, so the temperature does not decrease, as before menstruation, but, on the contrary, increases.
What will the definition of the day of ovulation
Knowing which day the oocyte leaves the follicle, a woman can:
- plan pregnancy: after 3-4 months of charting, you can practice sexual intercourse not “approximately”, counting 14 days from the expected start of the next menstruation, but knowing exactly the day of ovulation;
- to plan the floor of the future baby (the method is not 100%). If you want a boy to be born, it is better to have sexual intercourse on the day of ovulation (on this day the basal temperature decreases and the vaginal whites acquire the color and consistency of raw chicken protein). If the dream is to give birth to a girl, it is better to have sex 2-3 days before the expected ovulation;
- knowing when ovulation occurs, you can, on the contrary, avoid conception, since several days before it, the day of the egg’s release and the day after are the most “dangerous” days;
- the chart will show if there are hormonal problems, inflammation of the reproductive organs, or lack of ovulation (anovulation), which is why conception does not occur.
In addition, drawing a graph of basal thermometry in some cases will determine the pregnancy and without buying a test. And if you continue to lead him and the first time after conception, you can see in time the threat of miscarriage and take the necessary measures.
How to conduct basal thermometry
It is very important to know how to correctly measure basal temperature to determine ovulation. After all, a woman’s body is extremely sensitive to minimal changes in external conditions, and the units in which the schedule is kept are tenths of a degree (this is where the fluctuation by 0.1-0.05 ° C can be important).
Here are the basic rules, subject to which the temperature schedule will be as informative as possible:
- Measurements are carried out either in the rectum (optimally), or vaginally, or in the mouth (this requires a special thermometer).
- The thermometer must be inserted 2-3 cm and lie quietly, taking measurements, 5 minutes.
- Before taking measurements, sit down, spin, stand up, walk, eat is not allowed. Even shaking the thermometer can lead to a false result.
- Choose a high-quality thermometer (preferably mercury), with which you will measure the temperature daily for 3-4 months.
- Put on the table (shelf) near the bed, to which you can reach in the morning without getting up, 3 things: a thermometer, a notebook and a pen. Even if you start keeping your schedule on a computer – in online or offline programs, it is best to read the thermometer readings and immediately write it down with the number.
- Take measurements every morning at the same time. Plus or minus 30 minutes.
- Before measurements, it is necessary to sleep for at least 6 hours. If you get up at night, take measurements later, so that it takes 6 hours.
- Thermometry should be done at 5-7 am, even if you can sleep until noon. This is due to the daily biorhythms of the hormones of the adrenal glands and hypothalamus, which affect the basal temperature.
- The accuracy of measurements is influenced by trips, alcohol intake, physical exertion, sexual acts. Therefore, try at the time of basal thermometry to avoid these situations as much as possible, but if they happen, mark them in the schedule. And if you are sick, and a fever has developed, all measurements for the next 2 weeks will be completely uninformative.
When to start measuring basal temperature?
From the very first day of menstruation, that is, from the first day of the cycle.
How to keep a schedule?
You can do this on a squared paper by drawing 2 lines: mark the date of the month on the horizontal line (along the abscissa), vertical (axis of the ordinates) draw the same so that each cell denotes 0.1 ° C. Every morning, put a dot at the intersection of the thermometry index and the desired date, connect the dots with each other. In the evening, the temperature is not necessary to measure. Under the horizontal line, leave a place where you will take daily notes about the highlight and the events that occurred that could have affected the indicators. Above the measurement results, from day 6 to 12, draw a horizontal line. It is called cloaking and is used for convenience of decoding the schedule by a gynecologist.
We also suggest using the ready-made template of the basal temperature chart below, saving it to your computer and printing it out. To do this, move the cursor over the image and save the image through the right-click menu.
Note! If you are taking contraceptives, thermometry is not necessary. These drugs specifically disable ovulation, which makes them contraceptive.
Read also about other methods for determining ovulation in our previous article.
Basal temperature curve is normal
How does the basal temperature graph look like during ovulation (that is, with a normal ovulatory cycle):
- in the first three days of menstruation, the temperature is about 37 ° C;
- by the end of the monthly temperature indicators fall, amounting to 36.4-36,6 ° C;
- further, within 1-1.5 weeks (depending on the cycle length), thermometry shows the same figures – 36.4-36.6 ° C (may be lower or higher, depending on the metabolic processes in the body). It should not be the same every day, but fluctuates slightly (that is, it is not a straight line that is drawn, but zigzags). After 6 values, connected by a covering line, should be followed by three days, when the temperature becomes higher by 0.1 ° C or higher, and on one of these days – higher than 0.2 ° C. Then after 1-2 days you can wait for ovulation;
- just before ovulation, the thermometer shows the basal temperature lower by 0.5-0.6 ° C, after which it rises sharply;
- during ovulation, the basal temperature is within 36.4-37 ° C (according to other data, above 37 ° C). It should be 0.25-0.5 (on average, 0.3 ° C) higher than at the beginning of the menstrual cycle;
- what should be the basal temperature after ovulation depends on whether it was conceived or not. If pregnancy does not occur, the numbers gradually decrease, to a total of about 0.3 ° C. The highest temperature is observed at 8-9 days after the release of the mature oocyte. It is on this very day that the implantation of the fertilized oocyte into the inner uterine membrane takes place.
Between the average numbers of the two halves of the cycle – before and after ovulation – the temperature difference should be 0.4-0.8 ° C.
How long does basal temperature stay after ovulation?
Before the onset of menstruation. Usually it is 14-16 days. If 16-17 days have already passed, and the temperature indicator is still above 37 ° C, this most likely indicates the occurrence of pregnancy. During this period, you can make a test (most importantly, after ovulation has already passed 10-12 days), you can determine the hCG in the blood. Ultrasound and gynecologist examination are still uninformative.
These are indicators of the basal temperature of ovulation, as well as before and after it. But not always the menstrual cycle looks so perfect. Usually the numbers and the type of curve cause many questions for women.
High numbers in the first phase of the cycle
If, after menstruation, basal thermometry figures are above 37 ° C, this indicates an insufficient amount of estrogen in the blood. An anovulatory cycle is usually observed. And if you take 14 days from the next menstruation, that is, look at phase 2 (otherwise it is not visualized), then there are sharp jumps in temperature indicators, without gradually increasing them.
The syndrome is accompanied by various unpleasant symptoms: hot flushes, headaches, cardiac arrhythmias, and increased sweating. This type of temperature curve, together with the determination of low levels of estrogen in the blood, requires the doctor to prescribe drugs – synthetic estrogens.
Progesterone and Estrogen-Progesterone Deficiency
If, after ovulation, the basal temperature does not rise, this indicates progesterone deficiency. This situation is a common cause of endocrine sterility. And if conception does occur, then there is a danger of miscarriage in the early period, until the placenta forms and assumes the function of progesterone production.
The lack of work of the corpus luteum (a gland that forms at the site of an exposed follicle) is indicated by a decrease in temperature indicators as early as 2-10 days after ovulation. If the length of the 1 phase of the cycle can still vary, then the second phase should be the same and average 14 days.
Progesterone deficiency can also be assumed with an increase in numbers to just 0.3 ° C.
If you already have 2-3 cycles after ovulation – low basal temperature, refer to this gynecologist with this schedule. He will say on which days of the cycle it is necessary to donate blood to determine progesterone and other hormones in it, and on the basis of this analysis, will prescribe a treatment. Typically, the appointment of synthetic progesterone effectively, and as a result, the woman gets pregnant and bear the child.
This condition, when the ovaries do not produce sufficient quantities of both hormones, is indicated by the temperature graph, which does not have significant fluctuations (there are large areas with straight lines rather than zigzags). This condition is also evidenced by an increase in temperature indicators of only up to 0.3 ° C after ovulation.
If it is already 16 days of the menstrual cycle, and there is no characteristic decrease, and then the temperature did not increase, most likely, there was no ovulation. The older the woman, the more she has such cycles.
Based on the foregoing, basal thermometry is a simple and budgetary method for determining the days optimal for conception, as well as the reasons for which pregnancy may not occur. It takes only 5-10 minutes of time in the morning. No matter what performance you do not see, this is not a reason for panic or self-treatment. Contact your gynecologist with your schedules for several cycles, and you will be prescribed diagnosis and treatment.