Fertility Awareness Method

What is Fertility Awareness?

Fertility Awareness Method (FAM) refers to observing signs of fertility, and using that information to either prevent or promote pregnancy. When FAM is used to the exclusion of any other form of birth control, it is often called Natural Family Planning. FAM can be combined with non-hormonal methods (diaphragm, cervical cap, condoms, spermicides) to enhance its effectiveness.

How Does Fertility Awareness Work?

Hormonal changes that impact fertility also cause physical changes in a woman’s body. The main components of FAM include:

  • Observing cervical mucus changes
  • Observing changes in basal body temperature (BBT)
  • Tracking length of cycle (calendar)
  • Observing other signs

People practicing FAM may use any or all of these factors to predict the most fertile days of each cycle. Using all aspects is called symptothermal birth control.

Cervical Mucus Changes

A few days before ovulation, the body produces cervical secretions that are hospitable to sperm. These secretions, called “fertile mucus” or “spinnbarkeit,” are clear, slippery, elastic and abundant. At other times of the cycle, the secretions are thicker, often white or chalky. When mucus observation is used as a sole method of birth control, it is called the “Billings Method.”

Cervical Changes

The position of the cervix in the vagina may change throughout the month. The cervix may be softer and the os more open during fertile times. Women are often able to keep a chart of these changes along with their mucus observation chart.

Basal Body Temperature

Basal Body Temperature (BBT) is the temperature of the body at rest. A woman can check her temperature every day upon waking, and track this on a graph. BBT tends to be lower during and just after a woman’s period, and rise slightly (about .3 to 1.0 degree) at the time of ovulation. To prevent pregnancy, you must abstain from intercourse (or use a barrier method) until three days after that rise.


After keeping track of the menstrual cycle for several months, a woman can use the information to predict when ovulation might occur. It is important to track this for a period of at least sex months before relying on this for contraception, and to continue tracking while using the method. It is essential to consider both the shortest and the longest cycles. When used alone, this method is call the “rhythm method.”

Other Signs

Some women will notice other signs of ovulation such as a sharp pain in the lower abdomen, changes in libido or mood, or bloating. Using these signs alone is not effective birth control, but can be considered along with other signs to enhance the method.

How Effective is FAM?

As with other methods, effectiveness depends on how well this method is used. The more signs you track, the more effective the method is. The most effective way of using FAM is to avoid intercourse from the first day of the period until three days after all signs of ovulation (the post-ovulation method). Couples can modify this as they see fit with the understanding that each modification increases the risk of pregnancy.