Fertility Awareness Method (FAM)

What is fertility awareness (FAM)?

Fertility awareness (also called natural family planning or rhythm method) is a way to predict fertile and infertile times in your cycle. FAM is based on body signs, which change during each menstrual cycle in response to the hormones that cause ovulation (the release of an egg). If you use FAM and don't want to get pregnant, you must abstain (not have intercourse at all) or use another contraceptive during your fertile times.

What facts are Fertility Awareness Methods (FAM ) based on?

  • An egg is usually released once in each menstrual cycle.
  • The egg lives 12 to 24 hours.
  • Sperm can live up to five to six days in the uterus, and be able to fertilize an egg during this time.
  • This means that a woman is fertile for as long as six days before ovulation and two or three days after ovulation, a total of seven to eight days of fertility in her cycle each month.

When does a woman normally ovulate (release an egg)?

  • Ovulation normally occurs once in a menstrual cycle (between periods).
  • The egg is normally released 14 days before your period starts. If a woman has regular monthly periods (the number of days between the start of each period is exactly the same) then ovulation will occur at the same time during each cycle.

How effective is using FAM in preventing pregnancy?

  • If 100 couples use FAM for one year, an average of 25 women will become pregnant during that time.
  • If FAM is used perfectly, only 1 to 9 will become pregnant in the first year of use.
  • The effectiveness depends on many factors including the regularity of the woman's menstrual cycle and the ability to use the methods accurately and consistently.

How do fertility awareness methods work?

Some methods depend on abstinence during fertile times, others rely on a backup method of birth control, such as condoms and spermicide or a diaphragm, during fertile times. Having intercourse during your fertile time, of course, adds a risk of pregnancy since there is a chance of failure for any method of birth control.

Also, a spermicide placed into the vagina can make it difficult for the woman to observe mucus changes.

What are the different methods?

There are a variety of fertility awareness methods that use one or more fertility signs.

Calendar (Rhythm) Method predicts when ovulation will happen based on when ovulation occurred in past cycles.

Ovulation (Mucus) Method involves watching the changes in cervical mucus. Normal vaginal discharge changes at the time of ovulation. When you're most fertile, there is more mucus, and it feels wet and slippery (like raw egg white). After ovulation, there is less mucus and it's sticky, blocking sperm from entering the uterus. Women can check their mucus daily to tell when they're most fertile.

Basal Body Temperature Method (BBT) depends on taking daily temperature readings to determine when ovulation is occurring. There is a rise in temperature when ovulation occurs. By taking your temperature first thing every morning, and graphing the results, you can often tell if you've ovulated.

Sympto-Thermal Method uses a combination of various methods that identify symptoms of ovulation. These include the mucus method, basal body temperature, cervix changes, and other symptoms such as breast tenderness, abdominal heaviness, slight lower abdominal pain, or slight bleeding (spotting). This method may work better for women with irregular or less distinct mucus changes.

Advantages in using FAM for pregnancy prevention

  • Inexpensive, no health risks and convenient (no devices or hormones to use)
  • Acceptable to couples who have religious concerns.
  • Can develop greater communication, cooperation and responsibility for partners
  • Can be useful for determining optimum fertility time to achieve a pregnancy
  • Can help a woman track and improve PMS symptoms

Disadvantages in using FAM

  • High failure rate, difficulty in accurately predicting ovulation or fertile time.
  • Requires commitment from both partners. Cannot be spontaneous with intercourse.
  • Provides no protection against STIs.
  • Only as effective as the contraceptive used during fertile times (e.g., abstinence, condoms)

Other considerations

  • Many things can affect a woman's ovulation pattern, resulting in unintended pregnancies.
  • A woman must abstain or use another birth control method for several days longer than the actual fertile time
  • All fertility awareness methods depend both on careful, daily observation and charting of body signs, and on the cooperation of both partners in respecting fertile times.
  • The method works best to prevent pregnancy if a couple has a stable relationship, good communication, and strong motivation to use it correctly.
  • Some couples choose FAM because it's safe, less expensive than other methods, and requires no drugs or devices. It can be easily discontinued any time pregnancy is wanted.

Where can I get more information on Fertility Awareness methods?

You can get more information or referrals to organizations who specialize in how to use these methods by contacting SEX SENSE at 1-800-739-7367 or email,  or by visiting your local OPT clinic.

A good website that provides detailed information on how to use FAM is the Cedar Rivers Medical Clinics Fertility Awareness section.


Revised March 2009