Why There Isn't a Temperature Rise After Fertile Cervical Mucus

Fertile Cervical Mucus Without a Temperature Rise: What it Might Mean

Medical worker napping at hospital
Working the night shift may throw off your basal body temperature charting. This may lead to seeing fertile cervical mucus, but no temperature rise. Andersen Ross / Getty Images

If you are trying to get pregnant, you're likely aware that fertile cervical mucus and a sustained rise in temperature are two important signs that it's time. But what does it mean if you have days of fertile cervical mucus but your temperature seems to be all over the place? What could be causing this and what are the next steps?

Fertile Cervical Mucus, Temperature Rise, and Ovulation

Usually, fertile cervical mucus—a watery to raw egg-white like vaginal discharge—will precede ovulation.

If you're charting your basal body temperature, and ovulation occurred, you'd expect to see a sustained temperature rise within a few days of seeing your most fertile cervical mucus.

If you don't seem to get a temperature rise at all, it could be for a few different reasons. Let's take a look at the possible explanations.

Possibility #1: You May Not Be Ovulating

If you have fertile cervical mucus but no rise in temperature, it could be that you're not ovulating.

While fertile quality cervical mucus can warn you that ovulation is coming, so you can time sex for pregnancy, it doesn't confirm that ovulation actually took place. You can have fertile quality cervical mucus, but not ovulate. This is more likely the case if you also have irregular menstrual cycles.

Why would you get fertile cervical mucus if you're not ovulating?

Keep in mind that cervical mucus changes in preparation for ovulation.

The purpose of increased cervical fluids is to create a vaginal environment friendlier to sperm. Blood flow is also increased to the pelvic area, and this stimulates increased sexual desire. This is nature's way of trying to get you to have sexual intercourse when you are most likely to conceive.

So, if you're getting fertile cervical mucus, but not ovulating, you might want to think about it like your body is trying to ovulate, but not succeeding.

Normally, cervical mucus will become more abundant just before ovulation. Then, once an egg is released, the cervical fluids dry up. 

However, some women, such as those with polycystic ovarian syndrome or PCOS, may have days of fertile quality cervical mucus, followed by dryness, followed by another few days of cervical mucus. This is the body trying over and over again to ovulate.

Possibility #2: You May Not Be Charting Your Temperatures Carefully Enough

When charting your basal body temperature, you need to be meticulous about taking your temperature at about the same time every morning, before you get up and move around. If your readings aren't accurate you may miss the rise in temperature that corresponds to fertile cervical mucus.

This means taking your temperature at the exact same time on the weekends as you do during the week. (No sleeping in late!) It also means you must take your temperature before you get up to use the bathroom or move around much.

Do you work the night shift? Or have difficulty with sleep? These can also throw off your body basal temperatures.

Possibility #3: You May Be Part of the Small Percentage of Women Who Do Not Get a Temperature Rise

While most women will have a small rise in their basal body temperature after ovulation, there is a small percentage of women who do not get one.

You may be one of them!

How Can You Know if You're Ovulating or Not?

If you're unsure whether or not you're ovulating, see your doctor. They can do fertility testing to confirm or look for signs of regular ovulation.

To confirm ovulation is occurring, your doctor can order an ultrasound or blood work.

During an ultrasound, the technician will look for evidence of ovulation on the ovaries. Your doctor may want to schedule a ultrasound before you're expected to ovulate—to look for developing follicles—and then after ovulation—to look for evidence of a corpus luteum cyst. (This is what a follicle transforms into after it releases the egg.)

Most commonly, your doctor will order blood work to check your level of progesterone. Progesterone is a hormone that increases rapidly after ovulation, and then declines just before your period starts if you don't conceive.

What happens if you're not ovulating? Your doctor will conduct more fertility tests (including tests for your partner), refer you to a reproductive endocrinologist, or recommend fertility treatments.

Bottom Line on Fertile Cervical Mucus Without a Rise in Temperature

Most often, a women will experience changes in both her cervical mucus and a rise in basal body temperature near the time of ovulation. Carefully evaluating both of these can be very helpful in timing sex to occur at the time you are most likely to conceive. Yet sometimes a sustained rise in temperature does not occur despite fertile cervical mucus. As discussed, there are several possible reasons for this. For a few women, a rise in temperature doesn't occur despite ovulation. It could also be that you haven't been charting your basal body temperatures carefully enough—doing this properly can be difficult, but is even more challenging if you work an evening or night shift, or simply don't sleep well.

It's important to talk to your doctor if you experience a lack of body basal temperature change despite fertile mucus. Blood tests such as a progesterone level as well as ultrasound can help determine if you are ovulating or not. If you are not ovulating, further testing as well as consultation with a fertility specialist may be needed to decide upon the best way to get pregnant.

Sources:

Cunningham, F. Gary., and John Whitridge Williams. Williams Obstetrics. New York: McGraw-Hill Education Medical, 2014. Print.

Ecochard, R., Duterque, O., Leiva, R., Bouchard, T., and P. Vigil. Self-Identification of the Clinical Fertile Window and the Ovulation Period. Fertility and Sterility. 2015. 103(5):1319-25.e3.

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