Fertile Biomarkers: Basal Body Temperature

Basal body temperature (BBT) tracking is a popular method of fertility tracking used by many women to monitor and gather information about their menstrual cycles and optimise their chances of conceiving or to avoid pregnancy naturally. The technique involves taking and recording your temperature every morning immediately after waking up, before getting out of bed or engaging in any other activities.

Why Track Basal Body Temperature?

Basal body temperature changes throughout the menstrual cycle, rising after ovulation occurs and dropping before menstruation. By tracking your BBT, you can identify when you ovulate and predict when your next period will be due. This makes it a useful tool for fertility-awareness based methods of contraception or for increasing your chances of conceiving naturally. Additionally, tracking BBT can help detect hormonal imbalances or other reproductive issues that may affect fertility, as well as certain autoimmune conditions.

How to Track Basal Body Temperature

To track your BBT, you will need a basal body thermometer, which is more sensitive and accurate than a regular thermometer. In Celcius, this will give you two decimal places instead of one.

If tracking manually, you should take your temperature at the same time every day, and ideally at the same time each morning. To get an accurate reading, you must take your temperature before getting out of bed or doing anything else, as movement can affect the results, as can taking at a different time each day, sickness, alcohol consumption or a number of other factors.

For many women, these requirements can be a barrier to entry, maybe shift work, night waking to attend to children or other lifestyle factors would make it difficult to take your temperature every day at the same time, or without having woken multiple times through out the night. The rise of wearable BBT devices has been a huge leap forward in overcoming the common disturbances such as sleep, sickness or alcohol consumption, by continuously tracking and using tech to remove aberrant data, giving a more accurate BBT, all while reducing the mental load of BBT tracking. My favourite wearable, which I have used myself since 2020 is TempDrop – and they very generously give a 10% discount to my followers. {Use the code: NATURALFERTILITYCOLLECTIVE}

Make sure to record your temperature daily in a chart or digital app to easily monitor the fluctuations in your BBT, most wearable devices will automatically sync this information for you. You may notice a pattern of temperature changes throughout your cycle, with a sustained and significant increase indicating ovulation has occurred. This information can then be used to determine closure of the fertile window, and can be used to inform decisions about the timing of intimacy to avoid or achieve pregnancy.

Benefits of Basal Body Temperature Tracking

Besides helping you identify the fertile window, tracking your BBT allows you to spot any irregularities in your menstrual cycle. For instance, if you frequently experience unusually short or long cycles, early or late ovulation, or prolonged periods, it could be indicative of a hormonal imbalance, thyroid issues, or other underlying health conditions.

By tracking your BBT over several cycles, you and an experienced health professional that is versed in the symptothermal method (like me!) will gain a better understanding of your reproductive health, which can help address any issues and improve your chances of conceiving, or inform holistic care that manages your health issues.

Basal body temperature tracking is an effective and inexpensive way to monitor your menstrual cycles, detect ovulation, and assess the health of your luteal phase and progesterone production. With a few simple steps, you can easily track your BBT and gain valuable insights into your reproductive health.

Wanting to learn to chart and understand your fertile biomarkers to avoid pregnancy naturally? I have created Contraception: Naturally, just for you!

Or maybe you are preparing for pregnancy and want to supercharge your fertility and have clear insights into your cycles? Then Conceiving: Naturally is the perfect life-long investment for you and your family.

As always, if this article has raised questions – please feel free to reach out via Instagram or email.

Maddy x