Fertility Awareness Methods (FAMs)

What it is

Fertility awareness-based methods (FAMs) of birth control are those that track ovulation as a method of pregnancy prevention. They are also known as natural family planning methods.

How it Works

For this method to work, a woman must be familiar with her menstrual cycle and when pregnancy can occur. For a better understanding of how pregnancy takes place, refer to How Pregnancy Occurs. For a healthy woman, there are certain days when fertilization of her egg can take place and certain days when it cannot. Additionally there are some days when it is possible but unlikely.

A woman’s fertile days are determined by the lifespan of the egg and the sperm. Her egg lives for up to 24 hours after ovulation. Sperm can live inside a woman’s body for approximately six days. There is a chance of the sperm remaining alive up to five days before ovulation and then joining with the egg one or two days after ovulation. Unprotected intercourse can lead to pregnancy for about seven days of every menstrual cycle.

The key to the FAM method of preventing pregnancy is figuring out when the woman ovulates. This differs between women and sometimes for the same woman from one cycle to the next. There are three methods for predicting when a woman will ovulate: Temperature, Cervical Mucus and Calendar. For best results, women should rely on all three methods.

The Temperature method requires the woman to take her basal body temperature (BBT) throughout her cycle. She should take her temperature every morning as soon as she awakens. During the first part of her cycle, her BBT will be lower. Then it will rise slightly after ovulation (when the egg is released). It will stay elevated for the rest of her cycle, until it falls just before her period. To practice safe sex, she should not have unprotected sex until three days after she ovulates each cycle. She should also refrain from unprotected sex for five to six days preceding ovulation, in case the ejaculated sperm remains alive and fertile in her body.

The Cervical Mucus method is also known as the ovulation method or the Billings method. Cervical mucus is produced by the cervix to decrease the acidity of the vagina and to help guide the sperm through the cervix. During her period, a woman’s mucus is obscured by the flow. After menstruation, there are generally a few days without mucus known as “dry days.” If the cycle is long, these may be safe days. When the egg starts to ripen, more mucus is produced and appears at the opening of the vagina. It is usually yellow or white and cloudy. Usually a woman will have the most mucus just before ovulation and it will have a clear and slippery consistency; these are called “slippery days.” These are the peak fertility days. Women will want to avoid having unprotected sex these days. She should also use a secondary means of protection for three days after ovulation.

The Calendar method requires the woman to use the calendar to determine when she is fertile. The basics of this include keeping track of and recording the length of each menstrual cycle. She can circle on the calendar the day her period begins and count her cycle out from there. She needs to figure out when she ovulates, which differs between women and sometimes between cycles. She should record at least three months of her cycle to gather enough information to compare. Once she has an idea of how many days into her cycle ovulation occurs, she can engage in abstinence or use a secondary means of protection for the six days before ovulation and for three days post-ovulation.

Women using the FAM of birth control need to be committed to monitoring their cycles using one or more of the methods above. This method is only effective if participants are dedicated to adhering to the timeline.


  • The Temperature method has a success rate of 98% every year that couples use it correctly.
  • 97% of the couples that use the Cervical Mucus method correctly for one year will not become pregnant.
  • Of the couples that use the Calendar method correctly for one year, there is a 91% effective rate of pregnancy prevention.


There is no monetary cost associated with this method.


  • Women like the FAM because it can be used while breastfeeding, does not affect their natural hormones and does not carry any of the side effects of hormonal birth controls. Menstruating women of all ages can use this method.
  • FAM is a method that can be used by people whose religion does not allow them to use hormonal or barrier methods of contraception.
  • There is no monetary cost associated with FAM.


  • During fertile days, couples must either use a barrier method contraceptive, the pull out method or abstain from sex. Sometimes women have very irregular cycles and barrier contraceptives or abstinence must be used for months at a time while she gathers information about her cycle. Many couples may not have the motivation or discipline to follow through on this.
  • FAM does not protect against sexually transmitted infections (STIs) or HIV (AIDS).

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Do You Know Which Birth Control Method is the Most Effective?

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Do You Know Which Birth Control Method is the Most Effective?

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How effective is your birth control?

For sexually active women, he effectiveness of birth control depends on how perfectly they use it. For this reason, there are two kinds of effectiveness rates. One measurement is for perfect use, as the method is tested in the lab or used in real life with no mistakes.

The other is typical use, the average including people who don’t always use the method correctly or every time sexual intercourse takes place.

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