What is Basal Body Temperature Charting?
Basal Body Temperature charting (BBT) is a cheap, non-invasive way to monitor your menstrual cycle. It can be used to inform choices: it will give you more information so that you can decide your next steps in terms of medical interventions or investigations. In reflexology, we use it to best understand what is going on in your cycle so that we can adapt your treatment protocol accordingly.
Who should use this method?
It is suitable for all women who are interested in learning more about what is going on with their menstrual cycle, who are not using hormonal contraceptives. This may include women trying to conceive, women who are having issues with their periods (such as women with PCOS or irregular cycles), women towards the end of peri-menopause who may have long stretches between bleeds and want to have a better idea of when to expect another, women who expect that they are no longer having menstrual cycles and want to check.
What do you need?
You need a good quality digital thermometer with 2 decimal places. You can choose to chart the temperatures by hand using graph-paper but it is MUCH easier to use an APP. There are several out there but I recommend Fertility Friend, which is a free APP that you can use on your phone and your laptop. It’s by far the quickest and most efficient way to input your data and the APP will help you monitor and understand the results. Some women find that using Ovusense is easier and gets more accurate results, especially women who have broken sleep or who work shifts. Ovusense is a device that you wear overnight inside you like a tampon which records your temperatures through the night you get the most accurate result and directly feeds the information to the Ovusense APP. It takes away the element of human error and I have a discount code you can use if you think this option may be most suited to you.
How do you do it?!
If using Ovusense, then just follow the instructions in the manual. If using a digital thermometer, then make sure you have already downloaded an APP, such as Fertility Friend, onto your phone before you go to bed. Have your thermometer next to your bed such that you can reach out and grab it without getting up. You MUST follow the following rules to get an accurate result, otherwise your chart will be skewed:
Additional information for the APP.
There is the option to record other additional useful information into the APP. This gives a much more rounded picture of what is going on and will help the APP to identify ovulation much more accurately.
This could include information such as observations about cervical mucus (especially when it feels like egg whites), cramps, low mood, information from OPKs, spotting and when you have made love.
What does it tell me?
In a healthy cycle, there is a clear difference in the temperature of the follicular phase and the luteal phase, indicating a rise in progesterone due to ovulation. As such the graphs will show you if you have or haven’t ovulated. They cannot predict ovulation as they show you what has happened not what will happen BUT if you find that after 3 cycles you are ovulating on the same day then you can plan for this and ensure you make love in your ovulation window in the days leading up to ovulation. If there is no clear ovulation indicated then you have had what is called an anovulatory cycle, in that you have not ovulated. This is very useful information for any woman! The luteal phase needs to be 11-16 days in length if you are trying to conceive so this will give you information about this phase and you will be able to monitor the length of this phase and use it to inform you of your next steps in terms of seeking medical support. It will also tell you about the length of your follicular phase, which could again be a useful stepping-stone towards further medical investigation.