If you're trying to conceive or just trying to get to know your cycles, you've probably heard about basal body temperature (BBT) charting. It sounds a bit clinical at first, taking your temperature every morning before you even get out of bed, but really it’s just a way of spotting the tiny changes that show when you’ve ovulated. And since ovulation is the part of the cycle you actually need in order to conceive, it makes sense to know when it’s happening. Once you get into the habit it becomes second nature, and for many women it ends up being one of the simplest tools for working out your fertile days.
What is Basal Body Temperature Charting?
Your basal body temperature is your body's temperature at rest, typically measured first thing in the morning before you get out of bed. By tracking your BBT every day throughout your menstrual cycle, you can see patterns in your temperature that can help you predict when you're ovulating. This is because your BBT typically rises slightly after ovulation due to an increase in progesterone.
Why is BBT Charting Helpful for Fertility?
Knowing when you ovulate is crucial for conception, as you can only get pregnant when an egg is released from your ovary and travels down your fallopian tube. By tracking your BBT, you can get a better understanding of your cycle and when you're most likely to conceive. BBT charting can also help identify any issues with your cycle, such as irregular ovulation or a short luteal phase, which can affect your ability to conceive.
Tips for Accurate BBT Charting
To get the most accurate readings, there are a few things you can do to improve your BBT charting:
- Take your temperature at the same time every day, ideally first thing in the morning before getting out of bed. Take it before taking off covers, talking or drinking anything for the best result.
- Use a proper basal body thermometer, these have two decimal places so are more accurate for measuring small changes in temperature.
- Record your temperature immediately after taking it, a fertility tracking app is the best way to do this. You can find a range of paid or free options depending on what you're after. They will let you know automatically when you have ovulated based on a well tested algorithm, or can let you know if you haven't ovulated.
The Science Behind BBT Charting
There’s actually solid research behind BBT charting, it’s not just an old wives tale. Studies have shown that tracking your temperature is a reliable way to pinpoint ovulation, especially if your cycles are fairly regular. It gets even more accurate when you add in other signs, like changes in cervical mucus, because you’re spotting more than one clue at the same time. Put together, these small signals give you a much clearer picture of when your most fertile days are.
When tracking your BBT, it's important to know what to expect in terms of patterns and trends. A typical BBT chart should show a pattern of low temperatures during the first half of your menstrual cycle, which should increase by about 0.3 celsius and stay elevated for the remainder of your cycle. So if your pre ovulation temperatures were around 36 degrees celsius, they will jump to around 36.3 after ovulation. It's important to keep in mind however that every woman's BBT chart is unique and there may be some variations from month to month. What's most important is to look at the overall trend of your chart rather than individual temperatures. Ideally, your BBT chart should show a clear shift from low to high temperatures, indicating ovulation has occurred. If you see a consistent pattern of low temperatures without a clear temperature shift, this may indicate that you are not ovulating regularly or at all.
