The female reproductive system is utterly complex but also so amazing. The pituitary gland in the brain is like a conductor guiding the ebb and flow of hormone levels throughout the menstrual cycle to accomplish the feat of maturing an egg in the ovary, building up the uterine lining so that a fertilized egg has somewhere to implant and shedding that lining in the event that the egg is never fertilized. The entire time, your body is alerting you to your fertility in more ways than one if we take just a moment to listen.
Fertility awareness is not just about achieving pregnany; it is also used by many women as a hormone-free way to avoid pregnancy. When used correctly, the fertility awareness technique can be as effective as the oral contraceptive pill. I also recommend it frequently to my patients so they can learn more about their bodies and their reproductive health.
Women’s Fertility 101
The menstrual cycle is typically divided into three phases:
- Follicular Phase: the first part of the menstrual cycle, lasting from the first day of bleeding until ovulation is called the follicular phase. During this phase, your eggs are ripening in the ovaries in little sacs called follicules. The dominant hormone during this phase of the cycle is estrogen.
- Ovulation: At the end of the follicular phase, one egg will burst from the follicle into the fallopian tube, the passageway between the ovaries and the uterus. This is called ovulation. The released egg will live for 24 hours as it waits to be fertilized.
- Luteal Phase: The phase that occurs after ovulation until the day before you menstruate is termed the luteal phase. This period of time is dominated by the hormone progesterone and lasts for approximately 12 to 16 days.
During the follicular phase of your cycle (the first half), your basal temperature will be low, usually between 97.3°F to 97.8°F. After ovulation, your body starts to produce progesterone which raises the basal body temperature by at least 0.2°F. Your temperature will stay elevated until you get your next period. We can use these temperature measurements to guage where we are in our cycle (and therefore, when we are fertile)!
When temperature charting, it is important that your temperatue is taken every morning when you wake up before you speak, move or eat as these activities can change your temperature by small amounts. Drinking alcohol the night before, being ill, and taking your temperature at different times of the morning will also alter the temperature reading. If you find that your temperature is elevated compared to your usual reading, it is important to note if anything occurred which could have increased your temperature. Additionally, it is important to use a basal body thermometer to take your temperature as these thermometers give precise readings to two decimal places. This is important when we are trying to pick up on small shifts in temperature.
Factors that can affect your temperature
- Excessive movement
- Drinking alcohol the evening before
- A restless sleep
- Sleeping in a warmer/colder room
- Traveling to a different time zone
- Broken thermometer
The consistency of the mucus that is secreted from your cervix is also an indicator of you fertility. Have you ever noticed that the mucus changes from being thick to slippery depending on where in your cycle you are? In general, the more watery the mucus becomes, the more fertile you are. Under the guidance of hormones, the cervical mucus slowly changes from being thick to more watery the closer you get to ovulation. At peak fertility, the mucus is an eggwhite consistency and can be stretched between your fingers. This type of mucus is present to help guide the sperm to your egg. Who knew your secretions could tell you so much?!
To check your cervical mucus, either look at it after wiping with toilet paper or insert a clean finger into your vagina and reach for your cervix (this method is also helpful to guage the position of your cervix which I’ll talk about next).
- Egg White cervical mucus: This is considered to be the most fertile of all mucus types as it allows the sperm to easily into the cervix. The consistency is similar to raw egg white and can be stretched between the fingers.
- Watery cervical mucus: This is the second most fertile type of mucus after egg white cervical mucus. This type of mucus is clear in color and drips off of your fingers. You may find that it absorbs into your underwear throughout the day.
- Creamy cervical mucus: This type of cervical mucus is either white or yellow and is of a thick, lotion-like consistency. Creamy cervical mucus is considered to be unfertile as it restricts the movement of sperm.
- Sticky cervical mucus: Sticky cervical mucus is thick and tacky. This is the least fertile type of mucus as sperm have a hard time swimming through it.
When checking your cervical mucus, this is also an optimal time to check the position of your cervix. To find your cervix, insert one or two fingers into your vagina and reach backwards. The cervix will feel almost like the tip of your nose and is firmer than the surrounding vaginal walls.
The position, firmness and openness of the cervix varies with the menstrual cycle and is yet another clue to when you are fertile.
- While menstruating, the cervix is normally low, hard and slightly open to allow the blood to escape. The cervix will feel like the tip of your nose.
- After bleeding stop, the cervix will remain low and hard. The opening to the uterus (the os) will remain closed.
- As ovulation approaches, the cervix will rise up and begin to soften.
- During the fertile days, the cervix will raise up, become soft (the consistency of your lips), and the os will open to allow sperm to enter the uterus. At this point, you may not be able to feel your cervix because it is either too soft that it blends in with the walls of the vagina or it is too high to reach. The acronym SHOW will help you remember what a fertile cervix feels like: Soft, High, Open, Wet.
- After ovulation, the cervix will drop lower and harden to the consistency of the tip of your nose again.
- When pregnancy occurs, the cervix will rise up and become soft but the os will remain tightly closed.
Putting It All Together
Together, charting your temperatue, checking the consistency of your cervical mucus and the position of your cervix are great indicators to when you are most likely to become pregnant during your menstrual cycle. This information can be used to either become pregnant by engaging in intercourse during your peak fertile days or to prevent pregnancy by abstaining from sex during this time or by using an alternative method of protection (e.g. condoms, diaphragm, etc.).
This information can all be recorded by hand using a temperature charting template or by using apps on your phone that make the process easier. For example, my own personal favourite that I show my patients is Kindara that allows you to easily record your information on a day by day basis. They have even developed a basal body thermometer that integrates with the app to make the process even easier! (Side note: I have no affiliation with Kindara; I just happen to enjoy their app).
The fertility awareness method is most suitable for women with regular menstrual cycles that don’t change on a month to month basis. For women whose cycles vary in length dramatically each month, it is very hard to determine when you will ovulate and therefore, when you are fertile. In this case, you may want to work with a naturopathic practitioner to regulate your cycles and balance your hormones.
What Your Temperature Chart Can Tell You
Now that you know how to chart your temperature, let’s discuss how to interpret your chart.
- Fertile days: One mistake that couples who are trying to achieve pregnancy make is that they engage in intercourse after noting the temperature spike. Most of the time, by the time you see the spike, ovulation has already occurred and it is too late to try to fertilize the egg. The most optimal time to engage in intercourse is a day or two before ovulation. This is why it is important to learn what day in your cycle you ovulate on by studying past charts as well as paying attention to your cervical mucus and cervical position.
- How to avoid pregnancy: If you are trying to avoid pregnancy, there are two factors that you need to keep in mind. The first is that sperm are able to survive for 5-6 days in the uterus and can fertilize an egg during this time. The second is that the egg can survive for up to 24 hours. Therefore, the fertile window exists for as long as 6 days prior to ovulation and 2-3 days after ovulation. If you and your partner are trying to avoid pregnancy, it is crucial to use a second form of birth control during this time.
- Lack of ovulation: If you do not notice an increase in temperature during the second half of your cycle (monophasic chart as opposed to a biphasic chart) this indicates an anovulatory cycle (ovulation did not occur). If this is a regular occurrence, you may want to work with a naturopathic physician with knowledge in fertility to balance your hormones and increase your fertility.
- Pregnancy achieved: There are a few different clues that may indicate you are pregnant in addition to a standard pregnancy test. If your temperature remains elevated for more than 18 days this is one clue that you may be pregnant. Also, if you notice that your chart has a second temperature rise (a triphasic chart as opposed to a monophasic chart), this could also indicate pregnancy. Lastly, if your cervix softens, rises but remains closed, this is another indicator of pregnancy.
- Luteal phase defect: If you find that you ovulate consistently but are having a problem achieving pregnancy, it could be due to a luteal phase defect. This condition occurs when the luteal phase of the cycle is less than 12 days long. The egg needs at least 12 days in order to implant into the uterine wall and if your period arrives prior to 12 days into the luteal phase, you will have a difficulty getting pregnant. If you are experiencing a luteal phase defect, you may want to work with a practitioner knowledgeable in fertility to help you lengthen your luteal phase.
- Hypothyroidism: Your temperature charting can also alert you to a problem with your thyroid gland, the gland that is responsible for the metabolism in your body. If you basal body temperature is consistently below 97°F, this is one clue that you may have suboptimal thyroid function. Ask your naturopath about getting your thyroid tested if you have low temperatures in addition to symptoms such as weight gain, dry skin, constipation, fatigue and hair loss as low thyroid function can impair your fertility.
Now that you know how to perform the fertility awareness technique, give it a try and learn something new about your reproductive health!