What are fertility awareness methods?
Fertility awareness methods, also known as “natural family planning,” “the rhythm method,” or “periodic abstinence,” is a form of contraception that requires you to keep track of your menstrual cycle to determine the days that you can get pregnant. You don’t need to use any devices or drugs. There are fertility awareness methods that can be used alone or in combination to track the beginning and end of your fertile period (1).
Fertility awareness-based methods help you to predict when you are likely to become pregnant (your fertile days) and they rely on you avoiding unprotected vaginal sex on those days. These methods require you to be aware of changes in your body or to keep track of days based on the specific rules of your chosen method (2).
You can become pregnant during the fertile time of your menstrual cycle, which can often last between eight to nine days. During this fertile time, an egg is released from the ovary (a process called ovulation) and can live up to 24 hours. Sperm, however, can live inside your reproductive system for up to seven days. If sperm is present when the egg is released, the sperm and egg can join, which can result in pregnancy. It’s important to know that if you have unprotected sex as much as seven days before ovulation, it is still possible to become pregnant (3).
Fertility awareness-based methods are simple. You track your menstrual cycle and do not have sex on the days that you can get pregnant. If you have sex on those days, use an alternative method, like a condom—external or internal—or a diaphragm
What are the different types of fertility awareness methods?
There are several methods that you can use to monitor your fertility and determine the days within your cycle when you can get pregnant. You will need to observe changes in your body to calculate where you are in your menstrual cycle. This will take a lot of effort and commitment. Before you choose this method, make sure you understand what you need to do. Be prepared to not have sex for seven days every month or to use a second method on those days.
Fertility-based methods are categorized into calendar- and symptom-based methods (4).
Calendar-based methods
Calendar-based methods require you to keep track of your menstrual cycle and identify the beginning and end of your fertile days.
Calendar-based methods:
The calendar rhythm method. The calendar rhythm method helps to predict your fertile days by studying your menstrual cycle for several months. A cycle starts on the first day of your period, and this is when you begin counting. To determine your fertile days, you should record at least 6–12 periods before using this method, then count the days in between the first day of each period cycle.
To determine the beginning of your fertile window, subtract 20 days from the length of your shortest cycle. To determine the end of your fertile window, subtract 10 days from the length of the longest cycle. You should avoid having unprotected sex during your fertile window (5).
You can use a memory aid, like a period app or menstrual wheel, or just mark your period days on your normal calendar.
If the days between your menstrual cycles is less than 27 days, this method is not recommended for you. It can only be used by women who have regular periods.
Standard days method (SDM). This method is recommended for women whose menstrual cycle is between 26 and 32 days. You will need to keep track of the days of your cycle and avoid having unprotected sex from the 8th to the 19th day of your cycle. Some women use colored beads (e.g. CycleBeads) to track their menstrual cycles, with white beads indicating days to avoid having unprotected sex (fertile days) or use a backup method (6).
How to track your cycle using beads
Symptom-based methods
Symptom-based methods revolve around the observation of signs of fertility, such as cervical secretions and basal body temperature. You are then required to avoid sex on the days when these symptoms are evident. These methods include
– the two-day method (TDM). You will check your vaginal discharge every day to determine whether you have cervical secretions. To avoid getting pregnant, you must avoid having unprotected sex on the day you see cervical secretions and the next day. If you decide to have sex, you should use another contraceptive, like a condom, until the secretions clear.
– the basal body temperature (BBT) method. This uses a woman’s body temperature to determine when she is likely to be fertile. After ovulation, a woman’s normal body temperature rises slightly. You are not likely to become pregnant in the period between three days after the rise in body temperature to the start of your next menstrual period. For this method, you need to track your body temperature every morning to determine whether or not you are ovulating. You will take your temperature every morning before you stand up and record it on a chart. This method is most effective when used in combination with the symptothermal method or the standard days method (1).
– the ovulation method. Also known as the cervical mucus or billing method, it involves the observation of cervical mucus to identify the start and end of a woman’s fertile window. Most days, a woman’s cervical mucus is thick and sticky, but when you are ovulating it becomes watery and slippery. You need to check your cervical mucus daily. You can get pregnant from the onset of your secretions (when your cervical mucus is clear, stretchy, slippery, and wet) until three days after it stops. Using this method in combination with the basal body temperature method or standard days method increases its effectiveness (5).
– the sympto-thermal method. This method combines multiple fertility awareness methods to predict the days you can get pregnant. Your body has many signs indicating that you can get pregnant, and this method tracks several of them at once. This includes how open your cervix feels, your basal body temperature, and your cervical mucus. Using two or more methods will help you to better prevent pregnancy (7).
How effective are fertility awareness methods?
– Fertility awareness methods are not very effective. They work best when practiced perfectly (8).
– With perfect use, they are 95–99% effective. With typical use, they are 76–88% effective (9).
Refer to the chart below for information on how effective each fertility awareness method is.
When are fertility awareness methods a good option?
– If you are trying to get to know your body better. Fertility awareness methods are a good way to discover your body patterns. You will notice any changes and better understand your menstrual cycle.
– If you don’t mind getting pregnant. If you do not use these methods correctly, their failure rate is high. If you are willing to explore fertility awareness methods, it is advisable to use a backup method, like condoms, while you are still learning to track your calendar and/or symptoms. But if you are not very good at fertility-awareness tracking and getting pregnant would be a problem for you, consider choosing another method of contraception.
– If you have total self-discipline. Both you and your partner need to agree to follow this method. You also need to know your body well.
– If you are okay with not having sex for a certain period within your cycle or using another barrier method during your fertile period. With this method, you will need to track the days you can get pregnant each month. On those days, you will need to either avoid sex or use a non-hormonal method of birth control. If you are not okay with not having sex or using another method of birth control, do not use fertility awareness-based methods.
– If you want a method with no side effects. This method does not add additional hormones to your body. Many people who use this method want something that does not affect their bodies.
