The symptom-thermal method of natural family planning involves monitoring and recording naturally occurring symptoms produced by your body during your menstrual cycle. By learning how these various symptoms work together and observing recurring patterns in your cycle, you can learn to determine when you ovulate and when you are fertile.
Sympto-thermal natural family planning may be useful if you are unhappy with your current form of birth control, interested in avoiding the side effects of other methods or just seeking to gain a better understanding of your overall gynecological health, notes Toni Weschler, author of “Taking Charge of Your Fertility.” Practicing fertility awareness can also help you identify your fertile phase if you are trying to become pregnant.
Basal Body Temperature
Your basal body temperature is your lowest temperature achieved during rest. After ovulation, which occurs about halfway through your cycle, hormonal changes in your body cause a slight shift in your temperature. Your temperature will remain elevated throughout the rest of your cycle, until your period starts again. By taking your basal body temperature every morning and recording it on a fertility chart, you will be able to identify when this temperature shift has taken place. If you are using the sympto-thermal method as a form of contraception, Planned Parenthood recommends avoiding unprotected intercourse for three days following your temperature spike.
Cervical Fluid
For several days preceding ovulation, you may notice a change in the amount and quality of your cervical fluid. According to Weschler, as your body prepares for ovulation, the cervix begins to release a sticky fluid, which gives sperm a medium in which to swim. Following menstruation, you should have a period of several days where you are dry. Weschler notes that it is safe to have unprotected intercourse on the evening of any dry day. Once you start to notice the presence of cervical fluid, you should consider yourself fertile. The fluid will change from a tacky, milky substance to a slippery, clear fluid that indicates peak ovulation.
Cervical Position
You can also monitor the position of your cervix in order to confirm your other fertility symptoms. During your fertile phase, your cervix rises, softens and opens in order to make it easier for sperm to enter the uterus. You can observe these changes by inserting a clean finger into your vagina until you feel the opening of the cervix. Check your cervical position at approximately the same time every day and in the same position. It may take several weeks before you are familiar enough with the normal position and feel of the cervix before you are able to identify any changes. Weschler notes that observing your cervical position is optional, but it may help you identify your fertile phase if either of the other symptoms is confusing or ambiguous.
References
- “Taking Charge of Your Fertility”; Toni Weschler; 2001.
- Planned Parenthood: Symptothermal Method
