Suvini Jayasekera, L.Ac, MTCM
Basal body temperature (BBT) is the body's lowest temperature, which is usually measured immediately after waking up and before getting out of bed. The BBT can vary slightly from person to person, but it is typically around 97-99 degrees Fahrenheit.
During the menstrual cycle, the BBT can fluctuate due to hormonal changes. In the follicular phase of the menstrual cycle (days 6-14), the levels of estrogen in the body begin to rise. This can cause the BBT to be slightly lower than usual.
After ovulation (around day 14), the levels of progesterone in the body begin to rise. Progesterone is a hormone that helps to thicken the uterine lining in preparation for pregnancy. This increase in progesterone can cause the BBT to rise slightly, usually by about 0.5-1 degree Fahrenheit.
Some people may choose to track their BBT as a way to predict when they are most likely to be fertile or to confirm that ovulation has occurred. It should be used with other signs to determine ovulations such as cervical position, and cervical mucus.
There are a few ways to track basal body temperature (BBT):
Use a basal body thermometer: These thermometers are designed to measure small changes in temperature and can be more accurate than regular thermometers. To track your BBT, you'll need to take your temperature every morning immediately after waking up, before getting out of bed. It's important to take your temperature at the same time every day and to use the same thermometer consistently.
Use a fertility tracking app: There are several fertility tracking apps available that allow you to input your BBT, as well as other fertility-related information such as cervical mucus and menstrual cycle dates. The app can then help you track your menstrual cycle and predict when you are most likely to be fertile.
Use a fertility tracker: Some fertility trackers are designed to be worn on the body and can track your BBT as well as other fertility-related information. These devices typically sync with a smartphone app that allows you to track your fertility data and predict when you are most likely to be fertile.