Basal body temperature (BBT) is the temperature at which the body is at rest. Monitoring basal body temperature can help women determine when they are ovulating and when they are most fertile. Measurement of basal body temperature is quite easy. After knowing your basal body temperature, you can record it in the form of a graph to determine the fertile period. Furthermore, this information can be used to help or prevent pregnancy.
Step
Part 1 of 2: Measuring Basal Body Temperature
Step 1. Prepare a basal body temperature thermometer
You can buy a basal body temperature thermometer at your local pharmacy or medical supply store. This thermometer is equipped with a special label for measuring basal body temperature. The digital basal body temperature thermometer allows you to take measurements quickly and get accurate results. This thermometer will make a sound when you finish measuring body temperature and display the results in the form of numbers that are easy to read so it is very easy to use when you just woke up from sleep and still feel sleepy in the morning.
- Some types of basal body temperature thermometers can also store measurement results. It's just that, you should still record the results of temperature measurements in a safer place such as in a notebook or mobile phone application.
- You can also use a regular (not digital) thermometer, such as a glass thermometer, as long as it's specifically intended for measuring basal body temperature.
Step 2. Have a thermometer in bed
The first thing you should do when you wake up from sleep is take your basal body temperature while still lying down, before moving, stretching, or even talking. The goal is to get accurate measurements while your body is still resting. Meanwhile, moving or even talking can affect the basal body temperature measurement and give false results. To make it easier to take your temperature in the morning, place the thermometer on your bedside table so it's easy to reach when you wake up in the morning.
If you are using a glass thermometer, shake it out before placing it on the bedside table. Thus, the thermometer is ready to use when you wake up from sleep
Step 3. Take your temperature immediately when you wake up, at the same time every day
Try to take temperature measurements at the same time every day. Set the alarm and try to take your temperature measurement within 30 minutes of the time you usually wake up so that the results don't vary much from day to day.
To get an accurate result, make sure to sleep for 3-5 hours before taking your basal body temperature
Step 4. Place the thermometer in your mouth to measure the temperature
You can measure your basal body temperature by placing the thermometer in the same place in your mouth every day. Leave the thermometer in your mouth for a few seconds to get an accurate result.
Some women take their temperature vaginally or rectally, especially if they have trouble getting an accurate result by mouth. Whichever method you choose, be sure to use the same method in one menstrual cycle. Always place the thermometer in the same place or at the same depth in the vagina and rectum
Part 2 of 2: Recording Basal Body Temperature in Graphs
Step 1. Immediately record the results of the measurement of basal body temperature
To be able to monitor it effectively, record the results of temperature measurements in the morning. Take notes in a book or enter them in a phone app. There are several applications that can display the results of the basal body temperature measurement in the form of a graph or chart. This information can then be used to better understand your menstrual cycle and ovulation period.
- Be sure to mark the days in the cycle (the date and month) on the horizontal axis. Meanwhile, mark the vertical axis with the basal body temperature range, which is 36.1°C to 37.2°C. Before ovulation, a woman's basal body temperature ranges between 36.1°C and 36.4°C. After ovulation, the temperature usually rises to 36.4°C to 37°C.
- You can also look up basal body temperature charts online.
Step 2. Look at the chart of basal body temperature after two menstrual cycles and notice the pattern
To get a clear picture of your fertility, record your basal body temperature for at least one or two menstrual cycles. This way, you should be able to see a clear pattern, such as an increase or decrease in temperature at the same time on both cycles.
Watch for temperature fluctuations of at least 0.1 degree Celsius over a 48-hour span on the chart. This is a sign that you are ovulating. This temperature change should exceed the highest temperature recorded in the previous six days. The basal body temperature of most women in the day or two before ovulation is 35.6-36.7°C
Step 3. Know the most fertile period in the menstrual cycle
For most women, the two days before the basal body temperature rises is the time of ovulation or the most fertile period. Remember that sperm can live for 5 days in the reproductive tract. So, if you want to get pregnant, try having sex two days before ovulation. On the other hand, if you don't want to get pregnant, avoid having sex from the start of your period until three or four days after your basal body temperature rises. However, you should not use this method as a contraceptive method until you have tried it for several months.
