- Find a Fertility Doctor or Clinic
- Fertility Health
- Trying to Conceive
- Female Infertility
- Male Infertility
- General or Unexplained Infertility
- Fertility Treatments
- Getting and Paying for Fertility Treatment
- Family Building Options
- LGBT Family Building
- Ask Dr. Fertility
- Fertility Forum
Your Fertility Appointment Today to Start Your Family Tomorrow
You are here
Basal Body Temperature (BBT)
The overall goal of charting your Basal Body Temperature (BBT) is to find out if and when you are ovulating. BBT is the temperature of your body at rest. A special BBT thermometer, the most precise thermometer available, can record your temperature to the tenth degree. To determine your BBT you must take your temperature first thing in the morning, before you get out of bed, eat, drink or go the bathroom. This will yield the most accurate results.
Why is My BBT Important?
BBT is one of the easiest (and cheapest!) ways to determine whether or not you are ovulating, as well as track your ovulation patterns over the course of several months. By taking your BBT everyday and charting the results, you will notice patterns in your menstrual cycle and hopefully determine when you ovulate.
What you are looking for is your body's temperature soon after ovulation occurs. Your Basal Body Temperature should be lower before ovulation (also called the follicular phase) and slightly higher (by at least 0.4 degrees Fahrenheit) after ovulation (also called the luteal phase). If this shift between the phases is recorded, you have ovulated. This temperature should remain elevated for about 14 days.
What Does My BBT Tell Me?
If you see a definite increase in your BBT each month, that indicates that you are ovulating and it will help you time intercourse in order to maximize your chances for getting pregnant. You can also use your BBT to tell you whether or not your luteal phase is long enough to sustain a pregnancy. To have an adequate luteal phase, your temperature should stay elevated for at least 12 days after ovulation.