What exactly does basal temperature have to do with fertile days? How do you measure it, and what does “basal” actually mean? Here are the answers:
What is the basal body temperature anyway?
When the body comes to rest in sleep, the body temperature drops to its minimum. It is the lowest right after waking up. That is why the basal temperature is also called the “wake-up temperature.” During the day, even a few minutes after waking up, the core body temperature rises.
How can you measure your basal body temperature?
The basal temperature is measured with a unique digital thermometer. This measures the temperature to two decimal places. The temperature should always be measured in the same part of the body, for example, in the mouth or vagina. Make a note of where you measure and only change after a completed cycle.
When do I measure my basal body temperature?
The basal temperature must always be measured simultaneously every day, in the morning immediately after waking up, before leaving the bed. For a meaningful measurement, you must sleep at least four hours every night. The tolerance window in the morning, where the temperature must be measured daily, is around four hours. That means you can sleep in on the weekend and still take meaningful measurements.
What can affect basal body temperature?
Illness, heavy alcohol consumption, or irregular bedtime (e.g., shift work) can affect the temperature. These disruptive factors must be documented and the temperature excluded if necessary to not falsify your calculation. Not everybody reacts in the same way, which is why there are no generally applicable disruptive factors that inevitably lead to temperature increases. Here each woman decides individually for herself whether she thinks the temperature could be distorted.
There is a list of defined disruptive factors that you can also find in the :
drug consumption
unfamiliar consumption of alcohol
short or disturbed sleep
going to bed unusually late
night sweats or freezing
late dinner
Partying late at night
Stress & excitement
Travel & change of environment
Time change
Colds or other illnessesTo exclude measurements in the Ovy app, activate the “Exclude temperature” field in the Basal temperature view. In addition, under “Disruptive factors,” you can document which factor may have influenced your temperature. An example: You had an increased alcohol consumption on Saturday evening and took your basal temperature on Sunday morning? Then it would help if you excluded the temperature on Sunday, as the value was influenced on that day. The excluded values are then taken into account accordingly by the algorithm. You do the documentation for the disruptive factor on the day on which it occurs. It is essential that you stick to the disruptive factors and don’t “cling to your curve.”
Measuring basal body temperature: How to do it correctly
The basal temperature is measured daily immediately after waking up (before getting up!). You must always proceed in the same way to rule out fluctuations and minor measurement errors as far as possible.
The easiest way to do this is to measure the temperature with a clinical thermometer.
For evaluation, it is best to start on the first day of your menstruation, i.e., at the beginning of your cycle.
Why should you measure your basal temperature in the morning?
During the day, the body is subject to natural temperature fluctuations of up to 2 ° C. According to the Federal Association of German Internists, exercise or eating can also raise the temperature. To obtain a comparable and unadulterated measurement result, the basal temperature should be measured in the morning.
How often should you measure your basal body temperature?
It would be best if you take your basal body temperature right after you wake up every day. If you forget to take your basal body temperature, it is not an immediate problem.
Of course, the more days of your cycle you have measured, the more accurate your basal temperature curve will be. Individual missing days make the evaluation a little more inaccurate, but you can still interpret the values.
By the way: Even if you only got up a few minutes ago and forgot to take the measurement, you should not do it. After getting up, it is already too late to take the wake-up temperature. So here you have to wait a day.
Where do you measure the temperature?
You can take your temperature rectally (anus), vaginally (vagina), or orally (mouth). The Federal Association of German Gynecologists recommends rectal measurement, as this is the least likely is prone to failure. Oral measurements are the least accurate.
An axillary measurement, i.e., a measurement under the armpit, is not suitable for measuring the basal temperature, as it is too imprecise!
With the different measurement methods, it is essential to note some unique features:
Rectal measurement:
Measurement time: 3 minutes
The most accurate measurement resultVaginal measurement:
Measurement time: 5 minutes
Readings about 0.2 ° C below the rectal result
Beware of the thermometer slippingOral measurement:
Measurement time: 5 minutes
Readings about 0.2 ° C below the rectal result
The thermometer should be placed under the tongue, and the mouth should be closed during the measurementMeasuring basal body temperature correctly: 5 valuable tips
Always measure in the same place.
Where is the best place to measure my basal body temperature? Decide on a measuring location and then only measure the temperature there.
Always measure at the same time if possible.
Here you have a tolerance window of about four hours. That means: At the weekend, you can sleep a little longer, and the measurement remains meaningful
Always use the same thermometer
This way, you can avoid measurement inaccuracies
Use a thermometer that measures at least two decimal places
The temperature increase is usually only in the range of a few tenths (0.3-0.5) degrees
Get enough sleep
You should have slept for at least five to six hours before taking the measurement.