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Getting Started on the Symptothermal Method

This on-line document explains how a woman can learn to identify her fertility signs and symptoms. Women wishing to use the Symptothermal Method to avoid or to achieve a pregnancy are advised to contact a qualified Natural Family Planning Instructor.


The Symptothermal Method consists of observing more than one indicator of the woman’s fertility. Most couples who use a combined or symptothermal approach use cervical secretions and Basal Body Temperature to identify the fertile time. Some women also check the position and feel of their cervix or use a calendar calculation as a “double-check” against cervical secretions to identify the start and end of the fertile time. Other minor indicators include noting ovulatory pain (mittelschmerz) or breast tenderness. Ovulatory pain refers to lower abdominal pain or cramping some women feel around the time of ovulation.

Basal Body Temperature (BBT)

The BBT is the body temperature of a healthy person on awakening. The BBT rises under the influence of progesterone. Most ovulatory cycles demonstrate a biphasic BBT pattern: lower in the first part of the cycle, rising to a higher level beginning around the time of ovulation, and remaining at the higher level for the rest of the cycle. By taking her temperature on a chart each day of her menstrual cycle, a woman can retrospectively identify when she may have ovulated. However, because the BBT does not give adequate advance warning of ovulation, it cannot be used to identify the start of the fertile time. Therefore, it is of limited use for a woman who wants to achieve pregnancy.

Figure 1. Temperature variations during a menstrual cycle

Figure 1 (above) illustrates the BBT variations during a model menstrual cycle of 28 days. In reality, the BBT may rise more suddenly or more gradually. The typical pattern of a lower temperature before ovulation, followed by a higher temperature immediately before, during, and after ovulation, can be disrupted by illness, stress, travel, or interrupted sleep.

Use the BBT to determine the postovulatory infertile time:

  1. Take your BBT every morning at the same time before getting out of bed (after at least 3 hours of sleep). A special calibrated thermometer makes temperature reading easier. Take the BBT orally, rectally, or vaginally, but take it at the same site each day so changes in BBT can be detected accurately.
  2. Record your BBT readings daily on a special NFP chart (similar to that in Figure 4). Connect the dots for each day so a line connects dots from day 2 to day 3, and so on.
  3. Your temperature will probably rise at least 0.4° F around the time of ovulation and remain elevated until the next menses begins. Your actual temperature and maximum temperature are not important, just the rise over the baseline (preovulatory) temperatures.
  4. If you have 3 days of continuous temperature rise following 6 lower temperatures, you have ovulated and your postovulatory infertile time has begun. To see the baseline and rise clearly on the chart, draw a line just above (0.1 degree line) the lower (preovulatory) temperatures. When you record 3 continuous temperatures above this line and the last temperature is 0.4 degrees higher than this line, your postovulatory infertile time has begun.
  5. If you cannot detect a sustained rise in BBT, you may not have ovulated in that cycle. A true postovulatory BBT rise usually persists 10 days or longer.
  6. Some woman notice a temperature drop about 12 to 24 hours before it begins to rise after ovulation, whereas others have no drop in temperature at all. A drop in your BBT probably means ovulation will occur the next day.
  7. To conceive. It is not possible to predict fertile days using BBT. By the time the rise is detected, you are probably in the infertile phase of your menstrual cycle and have missed the opportunity to become pregnant. A biphasic temperature pattern, however, can let you know you are probably ovulating normally.
  8. To avoid pregnancy. Because the ovulation may occur as early as day 7 of the menstrual cycle, assume you may be fertile from just after menses (if your cycles are no less than 25 days in length) until your temperature has remained elevated for at least 3 consecutive days. The most effective way to use BBT charting when avoiding pregnancy is to avoid intercourse all through the first part of your cycle,until the temperature rise indicates you have ovulated.

Note: Because BBT does not provide information about the beginning of the fertile time, it is rarely used as the only fertility indicator by a woman who is using NFP.

Cervical Secretions

Changes in cervical secretion signal the beginning and end of the fertile time, even among those who have irregular cycles. Observe your cervical secretions by “the look, touch, and the feel”:

  • Look at the secretions on your undergarments, fingers, or toilet paper to determine its color and consistency.
  • Touch the secretions to determine their stretch and slipperiness.
  • Feel how wet the sensation is at your vulva when you are walking.

When they first appear, the secretions may be scant but sticky and thick with a cloudy color. Highly fertile secretions are clear, stretchy, wet, and slippery. Ovulation most likely occurs within 1 day before, during, or 1 day after the last day of clear, stretchy, slippery cervical secretions. When you are observing your cervical secretions, do not douche, because it can wash out the secretions, making it very difficult to notice changes.

Figure 2. Cervical secretion variations during a menstrual cycle.

Use your cervical secretions to identify the beginning and end of the fertile time:

  1. 1Observe your cervical secretions every day, beginning the day after your menstrual bleeding has stopped, and record them daily on a special chart (see Figure 2). To help you avoid confusing cervical secretions with semen and normal sexual lubrication, some counselors advise complete sexual abstinence throughout the first cycle.
  2. Check secretions each time before and after you urinate by wiping (front to back) with tissue paper. Note and record the color and appearance (clear, or cloudy) and consistency (thick, sticky, or stretchy) of the secretions, and how they feel (dry, wet, or slippery). Record how much they stretch when pulled between your thumb and index finger. Also, note and chart the sensations of dryness, or wetness at your vulva. Always record the “most fertile” observations you see during the day.
  3. Note the typical pattern in the cervical secretions:
    • During menstruation, blood masks any other sensations of wetness or secretions.
    • After the menstruation, the vagina may feel moist a few days, but not distinctly wet. There usually are no observable secretions. (Some women do not have any of these dry days, especially if they have very short cycles.)
    • Next may come secretions that are thick and sticky, cloudy. The vagina still does not feel distinctly wet. This can last for several days. Consider these days as fertile.
    • As ovulation nears, your secretions usually become more abundant, and you will have an increasingly wet sensation. Secretions become clear and slippery and can stretch 2 to 3 or more inches between the thumb and forefinger. The peak or last day of wetness or clear, slippery secretions is assumed to be about the time of ovulation.
    • After ovulation, the secretions become thick, cloudy, and sticky or disappear until the time of the next menstrual period.
  4. Douching, vaginal infection, semen, foam, diaphragm jelly, lubricants, medications, and even the normal lubrication of sexual arousal may interfere with the ability to notice a clear-cut secretion pattern.

To conceive. Have intercourse when cervical secretions are present. The probability of conception is greatest when the secretions are clear, stretchy, and slippery.

To avoid pregnancy. Check for secretions as soon as your menses are complete. (Some counselors recommend avoiding intercourse during menses because it is difficult to detect secretions when they are mixed with menstrual blood.) You can have sexual intercourse on preovulatory days if no secretions are present. (Some counselors recommend abstaining the next day and night following intercourse to allow time for bodily fluids to drain out of your body so you will not confuse semen and arousal fluids with cervical secretions. The following day, check your cervical secretions.) The fertile time begins when cervical secretions are first observed until 4 days past the peak day (the last day of clear, stretchy, slippery secretions.)

See Figure 3 (below) for an example of a chart completed by a woman using BBT, cervical secretions, cervical position and feel, and other minor indicators.

Figure 3. Symptothermal variations during a model menstrual cycle

A blank chart and a sample completed chart may be downloaded here. Instructions for using the chart are available on the Natural Family Planning Chart and Information Page.

Fertility Awareness: Beyond Family Planning

Learning about their fertility is important for men and women, regardless of which family planning method they use or whether they choose to use family planning at all. Information about their fertility and the skills to apply this information to oneself is called “fertility awareness”. Fertility awareness increases peoples’ knowledge of their reproductive potential and enhances self-reliance. Some couples like the active involvement required of the male partner, who learns about his own and the woman’s fertility and then abstains from intercourse when the woman is fertile. Fertility awareness information can be used for a number of purposes:

To conceive. Couples have intercourse on days the woman is potentially fertile. These include the days she observes cervical secretions or notes that her cervix is relatively soft and open. The chances of achieving a pregnancy are greatest when the woman observes clear, stretchy, slippery secretions. Conception is most likely to occur within 1 or 2 days of peak mucus (secretions).

To detect pregnancy. A postovulatory temperature rise (see the section on “Basal Body Temperature Charting”) sustained for 18 or more days is an excellent early indicator that pregnancy is under way.

To avoid pregnancy. For maximum effectiveness, couples should abstain from intercourse during the entire fertile time as indicated by the NFP method.

To detect impaired fertility. Charting fertility signs costs relatively little and can aid in diagnosing and treating fertility problems due to infrequent or absent ovulation. Women who do not ovulate tend to have a meandering BBT pattern throughout the cycle, rather than the typical biphasic pattern (lower in the first part and higher in the second).

To detect a need for medical attention. Changes in cervical secretions, abdominal pain, and other signs may indicate the need for medical attention.