How to Measure Basal Temperature

Measuring basal temperature is a crucial step in pregnancy planning. Along with tracking ovulation, this technique helps recognize the occurrence of ovulation and determine the best time for conception. It’s not as simple as it seems.

What is basal temperature

Basal body temperature is measured immediately after waking up, without getting out of bed. This is the lowest temperature during the day. It also helps to know when ovulation occurs. In general, BBT reflects the functioning of the ovaries at various stages of the menstrual cycle.

Why measure it

Basal temperature is a universal indicator of women’s health status. It helps determine the menstrual cycle phase, detect deviations, and identify ovulation onset.

The main purpose of measuring rectal temperature is to chart temperature changes as the woman’s hormonal background changes. 

1. For example, during ovulation, the hormonal levels in a woman’s body spike sharply, leading to a temperature rise of 0.4°C — 0.8°C. This day is considered the most favorable for conception. If the measured temperature is below normal, this day is considered the least favorable for conception.
2. Basal temperature also allows for an instant determination of the cause of menstrual delay. With normal temperature, one can speak of a temporary disruption in the body.
3. Track basal temperature charting for infertility, dysfunctions, and bleeding. The temperature chart helps identify luteal phase insufficiency, determine the presence of endometriosis, and detect acute inflammatory processes in the body.

As you can see, measuring basal temperature serves many functions. Each one helps a woman better understand her body and manage its processes.

How to Measure Temperature to Determine Pregnancy

Discovering basal temperature is not an easy task. Understanding your body comes only through attention and a high level of discipline. 

It is also necessary to follow a number of rules to ensure the measurement is accurate. It should be noted that accuracy plays a key role in the process since now even fractions of a degree are significant for you.

So, we have compiled a set of rules to help you accurately measure temperature to determine pregnancy and create an effective chart of its changes:

1. Measure temperature exclusively with a high-precision device. This will allow you to accurately determine your basal temperature.
2. Do not change the thermometer during one cycle. Each measuring device has individual inaccuracies. In regular use, 0.5 degrees may not matter much. When measuring basal temperature, this is a significant deviation.
3. Conduct a rectal measurement in the morning without getting out of bed. Prepare the thermometer the night before and place it so you don’t have to make any sudden movements.
4. During the measurement, it is important to relax both mind and body. Don’t think about anything, don’t move. Try to remain in a half-asleep state.
5. The temperature is measured daily at the same time, regardless of your plans for the day, whether it’s a weekend or a workday schedule. Choose one time that you will repeat over and over.
6. It is important to have slept at least 3 hours before measuring the temperature.

Accurate determination of basal temperature will allow you to monitor changes in your body.

Additionally, when measuring temperature to detect pregnancy, it is necessary to pay attention to external factors that may affect its change. By being mindful of them, you can calmly assess the situation and avoid getting nervous over nothing (which is strictly not allowed during pregnancy).

1. In the presence of viral diseases, the overall body temperature rises, leading to an increase in basal temperature.
2. Conditions of the rectum, which often accompany pregnancy, such as hemorrhoids, fissures, diarrhea, etc., can lead to increased readings.
3. Skin inflammation in any areas of the body.
4. Sexual intercourse shortly before measurement (even before going to bed).
5. Travel by airplane or a long car journey can have an impact.

If you realize that there are factors that may affect the temperature change, it is still worth measuring and recording it on the chart, but don’t forget to make a note.

What thermometer to use

To measure basal temperature with a thermometer, you can use either an electronic or a regular thermometer. The choice is yours. However, if you want to use an electronic thermometer, which is more modern, safe, and comfortable, remember the importance of choosing a quality device. Still, you could use a classic mercury thermometer. Important! A non-contact infrared thermometer is not suitable for determining basal temperature.

How to Measure Basal Temperature with a Regular (Mercury) Thermometer

If you don’t have an electronic thermometer and don’t want to buy one, you can check the temperature with a mercury thermometer. The measuring procedure is the same, with a few additions:

1. Be sure to shake the thermometer well before bed, so that in the morning you can set the thermometer with minimal movement.
2. When using a regular thermometer, it’s difficult to record the temperature to the hundredths of a degree. Therefore, choose the lower mark if the mercury column is “stuck” between two positions.

How Long You Need to Measure, Depending on the Chosen Method

The accuracy of measurement also depends on the time you spend on the procedure. For instance, if you choose an electronic thermometer, temperature measurement occurs up to the sound signal. This is how the thermometer indicates reaching the maximum point. If you’re checking the temperature with a mercury thermometer, 3 minutes is sufficient. After this, try to remove the thermometer as slowly as possible and record the temperature shown on it.

Creating a Measurement Chart

Before measuring basal temperature, it is necessary to create a chart of changes in readings. Only with its help will you be able to correctly track processes in the body and mark important ovulation days.

For a visual chart, two planes must have their values:

1. The horizontal plane denotes the calendar day, day of the menstrual cycle.
2. The vertical line represents the measured temperature data.

Also, when planning the chart, remember to leave space for notes next to each day. This will help you quickly jot down important nuances that might have influenced the temperature. Making notes is not only useful when measuring basal temperature to determine pregnancy, but also in any other cases.

For keeping records, you can use graph paper, but it is better to install an app that allows you to keep all the data at hand and record conveniently. The momslab.app will help you track changes in basal temperature, ensuring you won’t forget it during a doctor’s visit.

If you still decide to keep records on a regular sheet, follow a couple of rules:

1. Use one chart for one month.
2. On the vertical line at the 37-degree mark, outline a bold line. This will highlight more clearly the days when body temperature exceeded the norm.
3. Draw lines on the chart connecting the points of each day.

Monitor your health and track pregnancy, ovulation days, and cycle in a comfortable format with a mobile application.