What Is It?

Fertility awareness is a way to prevent pregnancy by not having sex around the time of ovulation (the release of an egg during a girl's monthly cycle). Couples who do want to have a baby can also use this method to have sex during the time that they are most likely to conceive. Fertility awareness can include methods such as natural family planning, periodic abstinence, and the rhythm method.

How Does It Work?

If a couple doesn't have sex around the time of ovulation, the girl is less likely to get pregnant. The trick is knowing when ovulation happens. Couples use a calendar, a thermometer to measure body temperature, the thickness of cervical mucus, or a kit that tests for ovulation. The ovulation kits are more useful for couples who are trying to get pregnant. The fertile period around ovulation lasts 6 to 9 days and during this time the couple using only fertility awareness for birth control who does not want to get pregnant should not have sex.

How Well Does It Work?

Fertility awareness is not a reliable way to prevent pregnancy for most teens. Over the course of 1 year, as many as 25 out of 100 typical couples who rely on fertility awareness to prevent pregnancy will have an accidental pregnancy. Of course, this is an average figure, and the chance of getting pregnant depends on whether a couple uses one or more of the fertility awareness methods correctly and consistently and does not have unprotected sex during the fertile period.

In general, how well each type of birth control method works depends on a lot of things. These include whether a person has any health conditions, is taking any medications that might interfere with its use, whether the method chosen is convenient — and whether it is used correctly all the time. In the case of fertility awareness, it also depends on how consistent a woman's ovulatory cycle is, how accurately a couple keeps track of when she could be ovulating, and how reliably unprotected sex is avoided during the fertile period.

Protection Against STDs

Fertility awareness does not protect against sexually transmitted diseases (STDs). Couples having sex must always use condoms along with their chosen method of birth control to protect against STDs.

Abstinence (not having sex) is the only method that always prevents pregnancy and STDs.

Who Uses It?

Fertility awareness is not a reliable way to prevent pregnancy for most teens. It is often very difficult to tell when a girl is fertile. Because teens often have irregular menstrual cycles, it makes predicting ovulation much more difficult. Even people who have previously had regular cycles can have irregular timing of ovulation when factors such as stress or illness are involved. Fertility awareness also requires a commitment to monitoring body changes, keeping daily records, and above all not having sex during the fertile period.

How Do You Get It?

For couples interested in this method, it is best to talk to a doctor or counselor who is trained in fertility awareness. He or she can then teach the couple the skills they need to know to practice this birth control method accurately.

How Much Does It Cost?

The tools needed for fertility awareness — such as ovulation detection kits and thermometers, for example — are available in drugstores. But they can be expensive. Again, it's best to talk to a doctor for advice on using this method.

Reviewed by: Larissa Hirsch, MD
Date reviewed: April 2010