Basal Temperature During Pregnancy

Knowing your basal body temperature can help you get pregnant if you want to, know if you already are, and if you are, make sure your pregnancy is progressing correctly.
Basal Temperature During Pregnancy

Last update: 09 September, 2022

Did you know that your basal body temperature can help you get pregnant? It might even give you clues as to whether you’re already expecting a baby. We’ll tell you everything you need to know about basal temperature in pregnancy in the following article.

Basal temperature is the temperature your body has when it’s at rest. It is, in short, the lowest temperature your body reaches.

When we’re trying to get pregnant, one of the methods for this is to calculate your basal temperature, as it fluctuates throughout the menstrual cycle. Although it’s true that, as a conception method, it’s not 100% accurate, it can help you out.

Using your basal temperature to get pregnant

Throughout your menstrual cycle, your basal temperature varies. This can help you find the days when you’re most fertile. It’s important to know the regularity of your menstrual cycles. To do this, measure your basal temperature for at least three months. Every day, before getting out of bed, measure and record your temperature.

An alarm clock, a calendar, and feminine pads.

The reason for taking the measurement as soon as you wake up is simple: We reach our lowest temperature at the moment when we wake up, so it’s the perfect way to know your basal temperature. In addition, it’s recommended that you’ve rested for at least five hours in a row. This will ensure that your body has reached a state of “rest”.

The measure should start from the first day of menstruation. You’ll notice that your temperature increases approximately 1ºF throughout the cycle until the end of it. The temperature rise occurs just after you ovulate. When you’ve been recording your temperature for several months, you’ll find a regularity in that increase in temperature, which will help you predict when it occurs.

Ovulation occurs two to three days before your temperature rise, and this is the perfect time to try to get pregnant.

Basal temperature to know if you’re pregnant

The increase in temperature during the cycle usually lasts 2 or 3 days after ovulation until the menstrual period starts again, at which point the temperature goes back down.

If when measuring your basal temperature, you verify that this increase in temperature is maintained beyond 18-20 days, at a measurement of approximately 98.6ºF, it’s likely that you’re already pregnant. If this happens to you, don’t hesitate to take a pregnancy test or see your doctor to make sure you’re expecting a baby. From there, the basal temperature in pregnancy will have different fluctuations.

“The symbiotic union has its biological pattern in the relationship between the pregnant mother and the fetus. They are two and yet only one”

-Erich Fromm-

Your basal temperature during pregnancy

Your basal body temperature during pregnancy won’t stay stable either. Early in your pregnancy and up to about week 10, your temperature will be higher than normal.

From there, it will drop again until it reaches the levels typical of the beginning of the cycle, practically at the end of pregnancy. This is due to the increase in progesterone. This hormone reaches very high levels at the beginning of pregnancy and drops from week 11-12. To alleviate this increase in basal temperature during pregnancy while you’re in the first trimester, you can take warm water baths or use wet cloths on your forehead or neck.

A pregnant couple writing in a journal.

Increased stress, fatigue, or the discomfort of pregnancy can aggravate the feeling of heat caused by the rise in temperature, so don’t hesitate to go to prenatal yoga sessions or do pilates for pregnant women. Your peace of mind will be key.

Warning signs

Although a rise in basal temperature in pregnancy is normal, you shouldn’t stop paying attention to it. If your temperature rises to 100.4º, go to your doctor in case this rise could be due to some type of infection. It never hurts to be cautious and stay under medical supervision during pregnancy.

A rise in temperature indicates fever and this is a sign that something is wrong in your body.

The basal temperature is, without a doubt, an indication that our body has to warn us of what is happening. If you’re trying to get pregnant or think you are, you can use your basal body temperature to find out. And in the event that you’re already pregnant, remember that your basal temperature can be one more ally to know that everything is going well.


All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.



This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.