What is Basal Body Temperature?
Your basal body temperature (BBT) is the lowest temperature your body reaches in a period of 24 hours. The normal BBT is usually between 97.2 and 97.7 Fahrenheit. Directly before you ovulate, your hormones cause the BBT to spike by anywhere between 0.4 – 1 degree. It remains elevated for the rest of your cycle (until your next period starts).
How can Tracking Basal Body Temperature Help Me With Fertility?
Did you know that it’s only possible to get pregnant at a certain point in your monthly cycle? To increase your chances of getting pregnant quickly, you need to get to know your ovulation cycle. The Basal Body Temperature Method involves charting BBT to identify your fertile window.
The key is to identify the spike in your basal body temperature and calculate when your fertile window is in each cycle. It’s easier if your menstrual cycles are a regular length and you take the temp at the same time each day. After charting BBT for two or three consecutive cycles, you should be able to see when your BBT rises and work back five days to find your fertile window.
If you have a normal and healthy reproductive system, your fertile window will be about five or six days long. The egg is only viable for 24 hours and sperm can survive in your body for five days. So, your fertile window is the five days leading up to ovulation. You should try to have sexual intercourse every second day in this part of your cycle. This keeps the sperm count high and gives you the best chance of conceiving a baby.
Basal Body Temperature Tracking to Conceive a Boy or Girl:
Some people claim that you can influence your Baby’s gender with BBT charting (the Shettles Method). This method promotes timing intercourse even more precisely within the fertile window for natural gender selection.
The theory has been largely discredited by fertility experts. But, while it’s fairly unlikely that you can actually select gender naturally, many women find it a successful way to understand their ovulation cycle and claim that BBT charting helped them get pregnant faster. And it’s cheap, easy to do, and completely harmless. What have you got to lose? Read on to find out how you can track and chart your BBT.
How to Take Basal Body Temperature:
You need to use a special Basal Body Temperature Thermometer because they are more sensitive and can measure minuscule differences in temperature. You need to set an alarm for the same time each morning and take the temperature before even sitting up in bed. Chart your BBT each day. On your second or third cycle, you should be able to identify when you are about to ovulate because of the spike in temperature. This is your fertile window – the very best time to try for a baby!
Note that there are other reasons for changes in BBT readings. If the times you take your temperature are irregular or you are unwell, you may see irregularities in your chart.
How to Chart Basal Body Temperature:
- Begin charting your BBT the day your period begins. This is day one of the menstrual cycle and the final day will be the day before your next period arrives.
- Record the exact reading each morning. Usually, BBT charts are grids, so you just plot the temperature and then join the line so that you can see any patterns developing.
- When your cycle is complete, look back and identify the day the BBT rose and remained elevated.
- Repeat the process through the next cycle and compare both charts. If the spike in temperature occurs on the same day, it should be easy to see when you ovulated and predict your ovulation date in the next cycle.
- In your third cycle, try and have sexual intercourse every second day in the five or six days leading up to the date you identified.
- Keep tracking your BBT throughout the process – if nothing else, it’ll make you feel like you’re doing something (re)productive while you’re waiting for that positive result!
Where Can I Buy a Basal Body Temperature Thermometer?
You can buy BBT kits in almost any drug store. They usually contain the special thermometer and a chart for recording your BBT. Some of the newest ones actually work with an app, making it even easier to record and track your BBT. You can also buy these products online. Check out some good examples here.
More Articles and Advice about Ovulation, Conception, Early Pregnancy, and More:
Preparing for Pregnancy: What health, dietary, and lifestyle considerations do you need to make when you’re planning to get pregnant? See our helpful checklist.
Trying to Conceive: A comprehensive guide to everything you need to know about fertility, ovulation, and trying for a baby.
Pregnancy Tests: Once you start trying, you’ll be eager to check whether your attempts have been successful. A guide to how pregnancy tests work, how effective they are, and when to use them.
The Earliest Signs of Pregnancy: What are the very first signs of pregnancy? We cover the signs and symptoms you might notice in the first few weeks of your pregnancy.
Week by Week Pregnancy Calendar: Find out about symptoms, fetal development and important advice for each week of pregnancy.