Triphasic Chart & Pregnancy: Does It Indicate You Are Pregnant?

Triphasic Chart – Is It a Pregnancy Sign

For couples who are eagerly anticipating the joys of parenthood, a small hint or sign of pregnancy can serve as a ray of hope that brightens their spirits. One intriguing and potentially telling indicator in the journey towards parenthood is a triphasic chart, a chart that displays three distinct temperature phases. But how reliable is this chart as a definitive sign of pregnancy? In this article, we will delve into the world of triphasic charts, exploring their potential significance and accuracy in detecting early pregnancy. We’ll examine the science behind them, consider their limitations, and provide guidance on interpreting and using triphasic charts as one of the many tools available to those navigating the path to parenthood.

What Is a Triphasic Chart?

So, what exactly is a triphasic chart? Well, this chart is a Triphasic BBT chart or basal body temperature chart women use to track their body temperature during three different phases of ovulation. Ovulation is biphasic, which means the temperature variations can be seen pre and post-ovulation. However, there is a third phase in which the body temperature also changes, and that takes place around a week to ten days after ovulation. This third phase is usually associated with a rise in the progesterone levels.

Also, towards the second half of the menstrual cycle (the luteal phase), progesterone is released to prepare the uterine lining for a fertilized zygote to attach or implant. Whether or not fertilization takes place, the ripening of the uterine wall will happen after each ovulatory phase. The increased amounts of progesterone hormones in the body result in increased body temperature. Therefore, triphasic basal body temperature (BBT) may not be a sure-shot sign of pregnancy. However, according to research, a chart indicating a triphasic pattern is more likely to be of a pregnant woman than a non-pregnant one.

How Common Is a Triphasic Chart?

According to a study, among the 150,000 women whose temperatures were recorded in BBT charts, 12 per cent of all women whose charts showed triphasic patterns were pregnant. Therefore, if your basal body temperature chart shows triphasic patterns, the chances are that you could be pregnant!

What Causes a Third Temperature Shift in the Triphasic Pattern?

The increase in the pattern can occur when you are pregnant, and when you are not. Let us understand how that may happen.

If you are pregnant, your body produces progesterone that prepares your uterine lining for implantation of the embryo and also suppresses ovulation and prohibits contractions in the uterine muscles that could cause the female body to reject an egg. Also, when the embryo attaches, or the implantation takes place, there is an increased production of progesterone, and this sudden increase can further spike the body temperature.

In case you are not pregnant, your triphasic chart may show temperature variations due to a number of other factors. A slight surge in the hormonal levels, an illness that may slightly increase the body temperature (not a fever), and changes in the bedroom temperature can affect your body temperature, too.

Does the Triphasic Chart Indicate Implantation?

Whether the triphasic chart indicates implantation or not, cannot be clearly stated because there is not much scientific evidence available to support it. There are just some empirical values available to support the claim. The process of implantation occurs only when there is an existing pregnancy. The important point of consideration is that the third phase of the temperature shift also starts happening when the implantation starts happening. For this very reason, there have been beliefs and claims that the triphasic chart is an indication of implantation. Sadly, there are not enough pieces of evidence on the triphasic pregnancy chart.

Is a Triphasic Chart a Sign of Pregnancy?

No, the triphasic chart is not a clear sign of pregnancy. Your triphasic chart can show temperature variations due to many causes such as the ones mentioned in the article above and not only because of pregnancy alone. You may be tempted to take an early pregnancy test if you see a triphasic pattern to confirm your pregnancy. However, we do not think that is a good idea because the pregnancy tests check for the hCG hormones and not the increased levels of progesterone.

If your progesterone levels are high, it does not mean that your pregnancy or hCG hormone levels are high too. And, if you take a test, the chances are that you may get a negative result, which may put you off. It is recommended that you wait until your period is late or until you have more high days (18 or more) on your chart to take the test. But, if you have a well-documented cycle curve, you can count days from your first high-temperature measurement to evaluate your chances of pregnancy. If you record more than 18 high days, well, it is quite likely that you are going to be a mommy!

When You Should Take the Pregnancy Test?

The most common and reliable time to take a pregnancy test is after you’ve missed your expected period. Most over-the-counter pregnancy tests are designed to detect the hormone hCG (human chorionic gonadotropin), which increases when you’re pregnant. It’s best to wait until a week from the day of your missed period or a few days afterwards for the most accurate results.


1. What Is the BBT of a Pregnant Woman?

The Basal Body Temperature (BBT) of a pregnant woman typically remains elevated, above her normal pre-ovulation levels, due to hormonal changes. It can be used as an indicator of pregnancy when it stays elevated for an extended period.

The BBT chart or your basal body temperature chart is a great parameter to know about your menstrual cycle and ovulation days; you can find out which days are your most fertile days in a month. Many women may feel excited to find changes in their triphasic pattern as a sign of pregnancy. Well, as discussed in this post, there are chances that you have a triphasic pattern, but that is not a clear indication that you are pregnant. Again, the most accurate indicators of pregnancy are your missed period and a positive pregnancy test. Therefore, relying solely on such indicators to confirm pregnancy may not be a viable thing to do.


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Also Read:

Is Diarrhoea a Sign of Being Pregnant?
Pregnancy Symptoms You Shouldn’t Ignore
Uncommon Signs & Symptoms of Pregnancy
How To Calculate Pregnancy By Months, Weeks & Trimesters?

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Gauri Ratnam completed her Masters in English Literature from the University of Pune. She began her journey as a German translator soon after completing her graduation, but later moved on to pursue her passion for writing. Having written for both digital and print media in a varied range of industries, she has the ability to write relatable and well-researched content, benefical for anyone seeking advice or direction.