Overview

The basal body temperature method — a fertility awareness-based method — is a type of natural family planning. Your basal body temperature is your temperature when you're fully at rest. Ovulation may cause a slight increase in basal body temperature.

You'll be most fertile during the two to three days before your temperature rises. By tracking your basal body temperature each day, you may be able to predict when you'll ovulate. This may help you determine when you're most likely to conceive.

If you're hoping to get pregnant, you can use the basal body temperature method to determine the best days to have sex. Similarly, if you're hoping to avoid pregnancy, you can use the basal body temperature method to figure out which days to avoid unprotected sex.

The basal body temperature method alone may not provide enough warning time to effectively prevent pregnancy. Often, people use this method in combination with other fertility awareness-based methods for avoiding pregnancy.