What is Basal Body Temperature?
Basal Body Temperature (BBT) is the lowest temperature your body experiences during sleep. It is determined immediately after waking up in the morning using a Basal Body Thermometer and should follow these guidelines, measured:
- At the same time each morning, +/- one hour
- After 3 consecutive hours of deep sleep
- Before getting out of bed to use the bathroom
How does it work?
In a healthy cycle, basal body temperatures will cluster in two sections: The first clear distinction of lower temperatures (before ovulation), and the second clear distinction of higher temperatures (once ovulation is confirmed).
Lower temperatures begin during menstruation. The number of days in this phase determines the length of our entire cycles, as it carries the most fluctuation in response to stress, alcohol, sleep change, etc.. How cool is that?
Once ovulation has occurred, BBT will rise approximately 0.8-1.0 degree F for approximately 12-16 days until your next period (this is your luteal phase).
The Rules of the Basal Body Temperature method
- You are considered infertile on the 3rd consecutive day that your temperature is above the COVERLINE. This temp shift confirms that ovulation has occurred. The three day mark is important because ovulation could likely happen 24 hours after your temperature shift. After this clear shift, you are considered infertile for the rest of your cycle.
- A Coverline is the horizontal line drawn on your chart .1 degree above the 6 temperatures prior to your temperature shift.
How Much Does a BBT Cost?
They range from $9 - $40. Choose one here.
What Are The Side Effects?
You will not get any side effects by using the Basal Body Temperature Method of birth control.
How Effective Is it?
99.7% Effective with perfect use, .3% Failure rate
97% Effective with typical use, 3% Failure rate
- Could support with getting pregnant
- Could support with preventing pregnancy
- Requires minimal daily attention
- Hormone free
- Promotes healthy body awareness, gaining self-confidence and self-responsibility
- Takes an initial time period to learn the method, as well as put it to practice (3 Months)
- Requires discipline and motivation to to chart regularly
- Requires correct and constant use for an effective outcome
- Does not prevent against HIV infection (AIDS) or any other sexually transmitted infections (STI’s)
Keep in Mind
Temperature readings could be affected by fever, restless sleep, varying work schedules, alcohol, etc.
PCOS (Polycystic Ovary Syndrome) or other hormonal disorders commonly have “false peaks” where ovulation does not occur. Recording daily BBT and CM is essential for clear self awareness.