
Fertility Awareness: All About the Rhythm Method

The fertility awareness method (FAM) of birth control is sometimes called the rhythm method or natural family planning. The idea behind it is to track your menstrual cycle closely so that you can avoid having intercourse on the days you’re most likely to become pregnant.
Dr. Marsha Bornt and her staff at Apple Hill Gynecology are happy to answer your questions about contraception. We offer several types of birth control, and if FAM is the best option for you, we want you to understand it thoroughly so that it’s effective.
Average vs perfect use
You’ve probably heard that the rhythm method is unreliable, but that depends on how you use it. When FAM to prevent pregnancy is used consistently and correctly — perfectly — fewer than five out of 100 women become pregnant. However, if you use FAM like an average person uses it, the effective rate drops to 76-88%, which means 12-24 women out of 100 become pregnant.
If you choose to use FAM and you don’t want to get pregnant, you need to be diligent and consistent or consider using a backup contraception. You must understand when you ovulate, which happens once each month, usually 12-16 days after your period ends. If you have unprotected intercourse within 24-48 hours of ovulation, you can become pregnant, but it’s important to remember that sperm can remain alive in your body for up to five days.
All of that means that you may be fertile anywhere from five to eight days. You may be fertile five days before ovulation, the day you ovulate, and 12-24 hours after ovulation.
More than one FAM
There are several ways to track your cycle, including:
- Standard days method
- Cervical mucus method
- Basal body temperature (BBT) method
- Symptothermal method
Read on to learn more about each of these methods.
Standard days method
This is sometimes called the calendar method because you track your cycle on a calendar for several months so that you can figure out if your cycle is between 26 and 32 days, which it must be to be able to use this method. Once you know exactly how long your cycle is, you either avoid vaginal sex or use an alternative form of birth control on days 8-19, which is your window of fertility.
Cervical mucus method
Your cervix produces mucus, and it changes at various points in your cycle. Just before ovulation, the amount of mucus increases significantly, and it becomes thinner and slippier. After ovulation, there’s less mucus, it’s thicker, and you’re less likely to notice it. To avoid pregnancy, you should avoid vaginal intercourse when you notice mucus.
Many things can affect cervical mucus, including medications, feminine hygiene products, breastfeeding, having a pelvic exam, and others.
BBT Method
Your basal body temperature is your body’s temperature when you’re resting. Most women have a slightly, 0.5-1 degree, higher temperature when they ovulate. Your most fertile days are the two to three days before your temperature rises.
You can track your BBT by taking your temperature each morning when you wake up and before you get out of bed. Record your temperature each day. Remember that your temperature only rises after ovulation and that having a fever can disrupt your tracking.
Symptothermal method
This is the combination of FAMs. For example, you may choose to combine the cervical mucus method and the BBT method. You may even choose to use all three methods.
If you have questions about birth control, or you’re considering using an FAM, consider scheduling an appointment at Apple Hill Gynecology. We can help you understand the risks and benefits of whatever type of contraception you’re considering.
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