How to take basal body temperature?


Basal body temperature is an indicator showing accurate inner body temperature. Its readings vary depending on the hormonal changes, muscle tension and other reactions of the human body systems. A normal basal temperature is a bit higher than the true body temperature depending on the activity a person performs during a day. One of the rules to take basal body temperature is to do it immediately upon waking in the morning in order to have the most accurate readings. The temperature is measured rectally.

You need a basal body temperature chart to analyze several criteria, such as:

  • Endocrine profile of a woman;
  • Hidden pathologies;
  • Pregnancy;
  • Infertile days.

Be aware that this method is not very reliable and each result should be verified by a doctor. As for basal body temperature charts in ovulation , use them as a method of contraception only when for some reason you can not use any other method.

Advantages and disadvantages of taking basal body temperature in pregnancy or before your period

There are not so many advantages of this method and major of them are:

  • Simple use;
  • No adverse effects on a woman’s body (concerning contraception);
  • A chance to detect pathology in the early stages of pregnancy.

Among the disadvantages of basal body temperature charts are:

  • This method is not predictive, it means that it shows only the current state and does not allow to predict the future (for example, basal body temperature before the ovulation is not indicative of its occurrence in the nearest future);
  • The method is not accurate as changes in the temperature chart may occur in several hours in a couple of days after the ovulation;
  • The absence of ovulation will be reflected in a temperature chart as well but the accuracy of the data will be low (the same applies to the yellow body functions);
  • measuring of the basal body temperature in ovulation is reasonable only when a woman is absolutely healthy, otherwise the readings will not be true.

Whatever result you may have according to the chart, there is no guaranty that it is true as there are too many factors influencing the reliability of the results. Incorrect basal body temperature measuring stifles the possibility to obtain reliable results.

How to take basal body temperature correctly?

There are several factors influencing the temperature and you should be aware of them:

  1. Physical activity. Even the slightest change of your body position upon awakening may spoil the results. Before going to bed, place the thermometer within easy reach so you don’t have to move much to get it. Of course, it is no use to take basal body temperature during the day or at night.
  2. Body position. As you should take basal body temperature immediately after waking, you should remain in a horizontal position. It is not allowed to stand up or to sit in bed. Any move enhances blood flow to the pelvic and the readings will be incorrect.
  3. Sleep. Before taking basal body temperature , you need to have at least 4 hours of sleep. Your body will have enough time to recover and slow down all the processes and you will get the most reliable readings.
  4. Sex. An interval between the last intercourse and temperature measuring should be at least 12 hours. To create a basal body temperature chart in pregnancy, you’d better abstain from sex.
  5. Breakfast. It is strictly prohibited to have a meal before measuring basal body temperature at home . Metabolism will be triggered shortly after a meal and cause the temperature increase. So take the temperature in fasting state.
  6. Medications. There are certain medications which have an impact on the readings of measurements and, consequently, they change the chart. In this case, you should visit your doctor to find out if the chart is correct and what caused changes in it. You should remember all the medications you were taking during measurements.
  7. Alcohol. A lot of alcohol before the day of temperature measurement will change the readings and give wrong results.
  8. Travels. Climate change and leaving your comfort zone is the factor changing the endocrine profile. Hormonal imbalance leads to incorrect temperature readings.
  9. Disorders. To predict ovulation by tracking basal body temperature , pay attention to the general condition of the body. Any infections or inflammations will provoke the temperature rise and the charts will be incorrect. For this reason, only healthy women can use the temperature method.

Considering all the dangerous factors, a woman may begin to take the temperature.

Apply some cream on the tip of the thermometer and insert into the rectum about a couple of centimeters. In 5-7 minutes remove the thermometer and write down its readings. Try not to move when taking the measurements.

Normal and correct basal body temperature chart

To make a correct temperature chart you can use a squared paper notebook or make the chart with the help of any software. One of the axes shows the temperature starting with 36 degrees and ending with the maximum fixed reading. Each section equals one-tenth of a degree. The second axis shows the day of the cycle. Be aware that one chart indicates the cycle (21-35 days in a norm) but not a calendar month. Each section here is one day of the cycle.

Normal chart readings in women of a fertile age should satisfy the following criteria:

  • In the first half of the cycle, the readings should not be over 37 degrees and in the second on the contrary. The chart should remind a «flying gull».
  • Basal body temperature during the period starting from the first day decreases to 37 degrees and to 36.5 degrees by the last day. One-tenth or two-tenth degree is a standard deviation.
  • For nearly half the days of each menstrual cycle, the temperature is a bit higher than 37 degrees and the rise is caused by the active ovum maturation (the exact number of days depends on the cycle duration).
  • Basal body temperature in the second half is around 37-37.5 degrees. This phase is called ovulatory and it is the most favorable period for getting pregnant.
  • Some days before the end of the cycle and the beginning of a new one the temperature decreases.
  • In a normal chart basal body temperature in the first phase should differ from the readings in the second phase for, at least, half a degree.

All these criteria are considered to be ideal and they occur very rarely. Besides, in a chart of a pregnant woman there can be several typical changes.

Basal body temperature chart in the early stages of pregnancy

The rules for taking the temperature are the same as for making a chart. However, normal readings will be much different. Criteria for normal basal body temperature in pregnancy are:

  • After the ovulatory phase of each menstrual cycle the temperature rises but it does not decrease later. The readings remain the same for a week or longer.
  • In a week, the temperature sharply decreases for one day only and this is a reliable sign of pregnancy. This phenomenon was named an implantation dip. In this very moment, the egg attaches itself to the uterine wall.
  • After the dip, the temperature rises again. Normal basal body temperature in pregnancy is 37 degrees and higher. It remains the same for several weeks until the level of certain hormones becomes lower. When the temperature begins to decrease, making charts is senseless.

Taking basal body temperature in pregnancy is not a very accurate method and additional examination methods are required.





basal temperature

Basal body temperature is of particular significance in missed miscarriage or when there is a of a misbirth. In these cases, a woman should be very attentive to the readings tracking the temperature decrease. When the temperature rapidly decreases, a woman should immediately visit a doctor as it may indicate that the level of important hormones is falling. An additional reason for concern is blood-tinged vaginal discharge and pain in the lower abdomen.

Basal body temperature in ectopic pregnancy sharply rises. The symptoms are similar to the situation with miscarriage and a woman should search medical assistance as soon as possible. However, temperature rise without any symptoms may also be the sign of inflammation in any body system.

Calendar birth control method

To obtain more accurate results the chart is created during several menstrual cycles (at least, three) and then a point where the readings of 37 degrees are overlapped is identified. If a woman has an ideal 28 days cycle, the point is 14. To the left and to the right of this point are 6 dangerous days.

If a menstrual cycle is 28 days, then safe sex will be during the first and the last weeks of the cycle. In all other cases, the days will be different but they are calculated in the same manner.

A six day interval is taken because the egg is able to wait for the impregnation for 6 days after ovulation. Besides, male sperm (according to some data) can live in a woman’s body for a week.

The method of tracking basal body temperature in ovulation depends on many factors and it is considered to be the least reliable method of contraception. Environment, psychological tension and other factors have a negative impact on the female hormonal level and, consequently, the temperature charts show incorrect results.

Readings indicating disorders

Taking basal body temperature after the period and during the entire cycle may result in unexpected changes. It can be a result of external factors influence or can indicate some disorders in the reproductive system.

The main criteria indicating pathologies:

  • Basal body temperature rise during the period may be a sign of inflammation in the uterus or endocrine profile disorders (estrogen levels reduction);
  • Increased temperature in the middle of the cycle is a norm. However, if it lasts for several days, it is better not to plan pregnancy as a woman may have some disorders with the egg;
  •  The duration of the second phase should be, at least, 12 days (depending on the cycle of fewer than two weeks), otherwise the egg does not have enough time for maturation and impregnation is impossible;
  • Delayed period and low temperature indicates ovulatory dysfunction;
  • If the difference between the temperatures in the two phases is less than half a degree, it may be a sign of infertility, especially if it repeats during each cycle;
  • If you noticed unexpected and short-term temperature rise, it means that some external factors have been involved or you broke the rules of taking basal body temperature;
  • There may be days in the chart when the temperature never reached 37 degrees and it means a complete lack of ovulation which is a norm (if it does not repeat during each cycle).

Due to the fact that basal body temperature can change very easily, it is recommended to make a chart during several months to get the most accurate results. And still it is not always possible to identify the logic of chart changes. It will be more reasonable to consult a doctor who can help you to interpret the chart and refer you to some additional examinations, if necessary. Anyway, it is not recommended to rely only on this method.