Monitoring Your Fertility: The Basal Body Temperature Method

You’ve probably already realized that timing is everything when you're dealing with fertility. Engaging in intercourse - or, if needed, using at-home insemination tools - at the right time is crucial for couples who want to get pregnant. The trick, then, is knowing when the time is right.

Because timing is so critical in successful conception, tracking the days where you’re most likely to conceive is often very beneficial for couples. Each month your body naturally gives you signs that you could be ovulating. All you need is a way to read them. There’s where family planning methods come in. Different family planning methods allow you to track these different signs of ovulation. Today, we want to help you determine if one of these methods - the basal body temperature method - is the right one for you to use.

What is the Basal Body Temperature Method?

Since timing is everything, understanding when you’re likely to ovulate is one of the best ways to increase your chances of conceiving. One way you can determine a likely ovulation date is by using the basal body temperature method. When using this method, you’ll track your basal body temperature or BBT. This the lowest temperature the body sits at in a 24 hour period. To track it, you’ll need to take your temperature when your body is still completely at rest - in other words, right when you’ve woken after sleeping.

While your BBT is generally fairly stable with only minor fluctuations from time to time, most women experience a slight and consistent rise in basal body temperature when they ovulate; their BBT then often stays slightly elevated until their next period. This rise may be as slight as .1 of a degree or as high as 1.0 degree. But even if this rise is just a tenth of a degree, it’s an important sign. By taking your own basal body temperature properly and charting it each day, you’ll be able to better determine if you have ovulated.

How To Use The Basal Body Temperature Method

Step one in using the BBT method is to purchase a basal thermometer. These specially made, large-scale thermometers are sensitive enough to measure minute changes in body temperature, unlike regular thermometers. Basal thermometers are available at most drugstores, and can be used orally, rectally, or vaginally.

Once you have your basal thermometer, you should get ready to use it on a regular basis. To get as accurate a reading as possible with the basal body temperature method, you’ll need to take your temperature with the same method (i.e. orally, rectally, or vaginally) every time. You’ll also need to:

  • Begin taking your temperature on the first day of your period - i.e. the beginning of your monthly cycle.
  • Take your temperature when you first wake up in the morning. And we mean first thing! You must take your temperature before you get out of bed, talk, eat, drink, have sex, or smoke in order to get an accurate reading.
  • Wake up and take your temperature around the same time every morning.
  • Sit and keep your thermometer in place for five minutes when using it.

Additionally, you’ll need to make sure you record your temperature in a chart each day, and as accurately as possible (meaning, within one-tenth of a degree). Not sure where to find a BBT chart? No worries: they’re available online or at your gynecologist's office, and are even often included with basal temperature thermometers. There are also apps available that you can use to collect this data, if you’d rather not use paper charts.

And that’s it! Simply taking your temperature regularly, with the right thermometer, can go a long way in helping in your conception process. Once your basal body temperature rises higher than the temperatures you've recorded during the previous six days, and stays at this level or increases for at least three days, it's likely that ovulation has occurred. In general, the temperature range after ovulation is between 97 to 99 degrees. It’s also often at least two-tenths of a degree greater than your temperature was during the previous week.

Pros And Cons of using the Basal Body Temperature Method

As with any method, there are pros and cons to keep in mind while you try to maximize your chances of getting pregnant. These are the most important points to keep in mind when deciding how to track your fertility cycle:

Pros of BBT

  • The basal body temperature is a natural, low cost way to track your body's patterns.
  • By charting your BBT for a few months and watching the dates where your BBT rises, you may be able to see whether there's a pattern to your cycle that can help you predict when you’ll ovulate each month. Having this information in advance can help you determine the best days to try and get pregnant.

Cons of BBT

  • There are outside factors that could make your resting temperature rise, which will affect the accuracy of your tracking chart. These factors include:
    • Lack of sleep or disturbed sleep
    • Illness or exhaustion
    • Emotional distress
    • Smoking
    • Alcohol consumption
    • Sleeping with an electric blanket
  • Dealing with an illness or failing to take your temperature immediately after waking up could both affect your chart and make any patterns that you find in it inaccurate. (If you experience one of these factors, it should be noted on your chart to help clarify the reading.)
  • It might take several cycles before you determine an accurate indication of ovulation. Many women have found that the first month of readings is not extremely helpful.
  • Some women may not see a clear monthly pattern emerge by recording their temperature. Since ovulation can occur at different times in your cycle from one month to the next, your BBT chart may not be effective at predicting when you'll ovulate.

Our Thoughts On The BBT Method

Like the calendar method, the BBT method is just one possible way you can track your ovulation cycle and increase your chances of getting pregnant, whether through intercourse or through the use of home insemination aids. Much like the calendar method, the BBT may be a great tool for many women. However, on its own it may not always be the best method for you personally. Fortunately, when used in combination with another method, it could quickly become a valuable resource in piecing together a complete picture of your fertility cycle.

So far we’ve only highlighted two of ovulation tracking methods available to women today. Stay tuned as we continue to explore these options and explain how you can determine your own likely ovulation date in the coming weeks.

Keep learning more about ovulation and fertility with these posts:

4 Tracking Tools to Use When Trying for a Baby

Starting a Family By Using the Calendar Method

Tracking Your Natural Fertility: The Cervical Mucus Method

Looking for a more affordable fertility option? Cervical cap insemination puts the sperm at the opening of the cervix, as close as possible, to swim up through to an egg, optimizing your chances of becoming pregnant. Learn more about The Stork OTC