What is basal body temperature

This is the body temperature of the body when it is at rest. During a women’s menstrual cycle, the basal body temperature shows two distinct phases. This is known as a biphasic pattern. It shows a lower temperature before ovulation and a slightly higher temperature after ovulation.

A sustained rise in BBT tells you that you have ovulated. Once ovulation has occurred, fertilisation can only take place within 12-24 hours before the egg is no longer viable.


How to get an accurate reading

In order too get accurate temperature readings that are easy to interpret, readings must be taken:

Immediately on waking before getting out of bed – This means before getting up to children, going to the toilet, eating, drinking or if your lucky enough; morning sex. If any of these things are necessary before taking your temperature, an accurate temperature reading can be taken after another 1 hour of sleep.

At approximately the same time every day – Sleeping in a few hours may cause a higher temperature reading.

Vaginally – This is the most accurate way to take a BBT temperature and will give a more stable reading. Under arm readings are close to useless for charting. Oral temperatures can be used but are not as accurate as vaginal.

Temperatures can be taken from day 1 or if you prefer you can start after the period has finished. If you tend to have short cycles it is important to take the temperature from day 1 in order to get a good baseline reading.

 

Things that can affect your temperature readings

  • Sleeping in
  • Eating a heavy protein meal the night before
  • Drinking too much alcohol the night before
  • Illness

If any of these things happen, be sure to write it on your chart, you may choose to ignore the reading if it doesn’t seem to fit.

 

More on this topic coming very soon. Check back in early November or contact me with your questions.