What are fertility signs and why are they reliable?

A simple description of natural family planning (NFP) is using knowledge of a woman's cyclical fertility to avoid or achieve pregnancy. The fertile window is determined by observing physical signs of fertility. ​Not terribly complicated, right? But what exactly are these fertility signs, and why can we trust them? Can a woman really tell if she's fertile simply by observing her body?

Fertility signs are physical biomarkers that reveal where a woman is in her menstrual cycle. Because the fertile window only occurs once per cycle, knowing when that window occurs is vital if a couple wishes to avoid pregnancy naturally (by abstaining during the fertile time), or if they are trying to conceive. Most fertility signs can be observed by the woman herself with no medical tests or specialized equipment. The signs commonly used in most  methods of natural family planning  are:

• Basal body temperature: A woman's resting or waking temperature, taken with a thermometer first thing in the morning
• Cervical mucus or cervical fluid: ​A special mucus produced by the cervix that is vital for fertility, acting to keep healthy sperm alive and filter out abnormal sperm, among other things.
• Cervical position: ​Subtle changes in the position and texture of the cervix itself
• Secondary signs: ​​​Breast tenderness, intermenstrual pain, and mood are interesting signs to note, though not reliable enough to be used alone to practice NFP.

Why fertility signs are trustworthy

The reason that fertility signs can be relied upon to detect a woman's brief fertile window is this: fertility signs are direct reflections of hormonal activity. Since women's sex hormones fluctuate in a very particular manner throughout the stages of her cycle, her fertility signs will show exactly what her body is doing.
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For example, a woman's basal body temperature will rise slightly in response to the hormone progesterone. ​Fertile quality cervical mucus is produced by the cervix according to a woman's estrogen levels. To a woman trained in fertility awareness, the presence of these signs is unmistakable and their timing tells the story of what her hormones are doing. Even though the moment of ovulation (the once-per-cycle release of an egg from an ovary) can't be detected without ultrasound, the hormonal events surrounding ovulation can be clearly observed through fertility signs. Because of this, a woman who uses NFP can confidently determine when her fertility begins and ends in any given cycle. 

The implications of this are widespread. As previously mentioned, the ability to determine when she is and isn't fertile gives a woman incredible control and flexibility in her family planning. Pregnancy can be avoided with no pills, devices, or barriers. A couple can also optimally time lovemaking for achieving pregnancy.

​But beyond family planning. learning to understand her fertility signs can help a woman to understand and monitor her health. Knowing her usual pattern of healthy cervical fluid will allow the woman to be the first to know if she has some kind of cervical or vaginal abnormality. Fertility charts, records of daily fertility signs, can reveal hormonal imbalances or other health issues.  Learning fertility awareness can truly enable women to be active participants in their own healthcare.  

Fertility signs are reliable, physical reflections of the day by day hormonal story of your cycle. Would you like to know more about how natural family planning works and why it's effective? Read some frequently asked questions or contact me!