Despite what we were told in our limited sex education as teenagers, for most women there is only around 5-6 days of each menstrual cycle that we are actually able to conceive. If you are trying to conceive, wanting to actively avoid pregnancy naturally or even just want to find out what is going on with your menstrual cycle, Basal Body Temperature (BBT) charting is the perfect tool for you.
Charting your cycle is the most accurate way of finding out exactly what is going on in your menstrual cycle. With your chart you are able to see your fertile and non-fertile window, when you ovulated, any hormonal imbalances, and even thyroid conditions that may be causing disharmonies within your body. Identifying these problems early in your fertility journey is essential to working on the solution and ensuring you have a happy and healthy cycle… Saving you time wondering why it might be taking so long to conceive.
What is BBT charting:
Basal Body Temperature (BBT) is your body temperature at rest, taken just as you wake up every morning. Your BBT changes throughout the menstrual cycle in relation to the hormone levels present in your body, specifically the shift between estrogen and progesterone. This allows us to use it as one of the primary fertility signs.
Your BBT is the only sign that confirms if you have ovulated during the cycle. It also is the only sign that will let you pinpoint (to as close a degree as possible) when ovulation occurred. All your other signs, such as cervical mucus, tell you that ovulation is approaching but cannot confirm that it did indeed happen.
Charting your BBT will also tell you how long your luteal phase is so you will know if it is sufficiently long to allow for a pregnancy to occur and when to test for pregnancy.
How does it work:
In your follicular phase, the time just after menstruation but prior ovulation, estrogen is dominate resulting in your BBT to stay relatively low, between 36.00 – 36.50 degrees. Your BBT rises after ovulation due to increased progesterone released from ovaries via the corpus luteum, this is known as the luteal phase. During the luteal phase your temperature should rises by about 0.20 degrees, usually between 36.50- 37.00 degrees. This temperature shift should remain high until your next cycle (the beginning of your next menstruation).
This results in a biphasic pattern, lower temperatures in follicular phase, a temperature shift after ovulation, followed by maintained higher temperatures in the luteal phase. Ovulation is detected retrospectively on a BBT chart as it is seen as the day BEFORE the temperature shift and remains high for at least 3 consecutive days. Your BBT will stay high and continue to rise if there is a pregnancy.
How to record your basal body temperature chart:
- Buy a BBT thermometer (AKA ovulation thermometer). You need one that goes to 2 decimal points. You can get one of these from any good chemist for cheap (for around $20) or we do stock them at the clinic. This is required to see the temperature shift from follicular phase (pre-ovulation) to the luteal phase (post-ovulation). This thermometer is essential as in some women the biphastic pattern (shift from low temps in your follicular phase to higher temps in your luteal phase) can be quite small and you may not be able to see an ovulation on your chart if you are only a normal digital thermometer with 1 decimal point.
- Take your temperature at the same time each morning, after at least 4 hours of sleep. In the early morning hours your BBT is at the lowest and continues to rise as the hours go on. Taking your temperature at different times give you an inaccurate chart. If you make sure you note this in your chart.
- Take your temperature before you do anything else (get out of bed, don’t talk, eat or drink anything) before taking your temperature. Again, this causes unwanted variation in your chart.
- Take your temperature either orally or vaginally. Mouth breathers sometimes see a lot of variation in their charts and may prefer to take their temperature vaginally to get a more accurate reading. Hold the thermometer in place for at least 4-10 minutes to ensure it gets an accurate reading.
- Variations to note in your chart: time, any illness (cold, stomach ache), interrupted sleep, alcohol intake from the night before, and high stress, as this may affect the temperature readings.
- Note: ovulation can be confirmed only retrospectively, once you have had 3 consecutive days of high temps above the cover line.
TIP: Work with a natural fertility expert so that they can help you to accurately read your chart and advise you how to better support your fertility health.
Apps for charting your BBT
There are lots of aps you can use to record your BBT but the best in, my opinion, is Fertility Friend……and it’s FREE!!! It can take a little bit of time to get used to, but it is a fantastic tool that makes charting a breeze!
All of our practitioners at Spring utilise this fertility monitoring method with their fertility patients in order to get a close look at exactly what is occurring in the women’s cycle each and every month. It is a great way to assess the health of ones fertility, monitor progress and adjust treatments and herbs accordingly to achieve the desired outcome of a happy, healthy pregnancy and baby sooner.. Learn more about our IVF Support Program or Natural Fertility Support Program here.
~ Philippa Dunstan
Philippa is our incredible receptionist at Spring Acupuncture and is currently studying her Bachelor of Heath Science (Acupuncture). Philippa has special interest in female health, fertility, pregnancy and children’s health. She is passionate about sharing knowledge and empowering women in the understanding their bodies throughout all stages of life. Philippa strongly believes acupuncture enables us to listen to our bodies, take time for ourselves, and optimise our bodies innate ability to restore health and well-being.