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How to Measure Your Basal Body Temperature

If you’re trying to get a handle on when you ovulate, then measuring and plotting your basal body temperature is one of the most popular choices people make. It can be a useful guide, but this method does have limitations, particularly for those with irregular cycles, or who live with polycystic ovary syndrome or other fertility issues – using past data to predict your current and future cycles can lead to inaccuracies and result in you missing your best chance to conceive.

As you can only conceive in a tight window of time around when you ovulate, pinpointing ovulation is really important when you’re trying to get pregnant, especially if you’re dealing with any challenges to your fertility – like PCOS, as described above.

Measuring your basal body temperature isn’t entirely straightforward, but OvuSense have some advice about the best methods to use and what you should include in your fertility plans.

What is Basal Body Temperature?

This is a complicated term that’s thrown around and it won’t be any good to you unless you understand it. It’s the low core temperature your body settles at when it’s totally at rest: deeply asleep. When your body temperature falls to this low, basic level, small changes over time can be very eloquent.

What Are You Looking For?

When you measure your basal body temperature, you’re looking for two key indicators for ovulation: many people (though not all) experience a drop small drop in temperature the day they ovulate, followed by the more widespread phenomenon of a .2 degree rise in temperature in the 72 hours following ovulation.

You can spot these patterns even if your personal average temperature is a bit different to average for the rest of the population, the important thing isn’t the specific number but that pattern of changes. This makes measuring your BBT a more universal tool than hormone tests, for example.

The Right Time

To get an accurate reading, you need to take your temperature at the right time. From the moment you wake up, your metabolism starts to speed up, which heats your body and the small changes to your base temperature are lost in the noise of a busy day.

OvuSense has addressed this problem by using a vaginal sensor, as opposed to an oral thermometer, which measures true fluctuations in your progesterone overnight and throughout your cycle. Our sensor also has a greater level accuracy than most oral thermometers, which tend to be accurate only to the nearest tenth of a degree and can therefore miss subtle changes in temperature that may impact the accuracy of your prediction.

BBT monitoring records your temperatures day by day and allows you to use this past data to map when you're likely to ovulate during future cycles. As previously mentioned however, this does not account for those with irregular cycles, or fertility issues such as PCOS, and can result in you missing your best opportunity to conceive. OvuSense overcomes this issue by using up-to-date information to predict ovulation 24 hours in advance that is clinically proven to b ecorrect 96% of the time!

Find out more about core temperature technology and fertility here