If you want to have a child, it is of course useful to know when you are ovulating. Among other signs, you can also measure your basal body temperature for this purpose. What exactly basal body temperature is, what you need to look out for when taking it and how it helps you to determine your fertile days are explained below.
The most important facts about basal body temperature at a glance
- Basal body temperature is the temperature of your body immediately after waking up.
- Before you ovulate, your basal body temperature drops by around 0.2°C, and after ovulation it rises by up to 0.5°C.
- If the egg has been fertilised, the basal body temperature remains elevated.
- The basal body temperature can be influenced by a lack of sleep and stress, among other things.
- It is important to be careful when measuring the waking temperature to ensure that it is meaningful.
- In addition to basal body temperature, other symptoms can help you determine your fertile days.
What is basal body temperature?
Basal body temperature is the body temperature that is taken immediately after you wake up. For this reason, basal body temperature is sometimes called waking temperature.
Basal body temperature is not always the same, but changes during the menstrual cycle. By taking your basal body temperature regularly and writing down your results, you can get a good overview of the fluctuations in your waking temperature.
What does basal body temperature have to do with fertility?
Changes in basal body temperature are directly related to changes during your cycle. Knowing how your temperature changes can give you valuable information about when your fertile days are. This knowledge is helpful, for example, if you want to get pregnant.
Basal body temperature at ovulation
Just before you ovulate, your basal body temperature drops by about 0.2°C. In the 48 hours after you ovulate, your basal body temperature drops by about 0.2°C. This is the same as when you ovulate. In the 48 hours after you ovulate, your basal body temperature will rise again. The temperature increase can be up to half a degree.
Basal body temperature in pregnant women
If the egg was fertilised during the fertile days, your basal body temperature will remain elevated. If this is the case, it is an early sign that you may be pregnant.
Basal body temperature before your period
Before your period starts, your basal body temperature drops again. If it does not remain elevated, you can assume that fertilisation has not taken place and that you will have to try again next month.
When is the basal body temperature taken?
As mentioned, basal body temperature is the temperature of your body after you wake up. Ideally, you should take your readings before you get out of bed. After you get up, your body temperature will rise. Your results will be distorted if you take your basal body temperature too late.
How accurate is basal body temperature?
Your basal body temperature can fluctuate for a variety of reasons. This can falsify the values and affect the validity of your measurements. If you want to use your basal body temperature to calculate your fertile days, it is important to take this into account when interpreting your results.
The following factors, among others, can lead to fluctuations in basal body temperature:
- Lack of sleep
- Sleep disturbances
- Excessive stress
Taking basal body temperature: What do you have to watch out for?
In order for your basal body temperature to give you the most reliable information, it is important that you measure it correctly. Keep in mind that errors in taking your basal body temperature can have a significant impact on the validity of your wake-up temperature.
Therefore, observe the following rules when taking your basal body temperature:
- Decide on a measuring method and stick to it.
- Always use the same thermometer to take your temperature.
- Take your temperature immediately after waking up, before you get out of bed.
- Make sure you always take the measurements at the same time.
- Get enough sleep and avoid unnecessary stress in your daily life.
Be aware that your basal body temperature will only give you reliable information if you monitor it over a longer period of time. Therefore, it is not enough to track it for one menstrual cycle. Instead, you should measure your waking temperature daily for several cycles before you put too much trust in the validity of the values.
Basal body temperature is not the only sign that can help you calculate your fertile days. There are several other ovulation symptoms that are useful in this context.
In addition to basal body temperature, look out for the following ovulation symptoms:
- Changes in cervical mucus
- Changes in the cervix
- Middle pain
- Ovulation bleeding
- Increased libido
- Breasts that are sensitive to touch
You can also take an ovulation test. This test measures the level of LH in your urine. Shortly before ovulation, there is an increase in luteinising hormone (LH). The ovulation test helps you to notice this increase.
As you can see, your basal body temperature can actually help you calculate your fertile days and get pregnant. If you want to have a baby, it is definitely worth investing a little time in measuring and documenting your basal body temperature.
However, it is very important that you do this carefully. Otherwise, the results will quickly be falsified and your basal body temperature will lose its significance.