Standard Days Method
Average Failure Rate: 12%
The standard days method (SDM) of natural family planning has replaced the old rhythm method as the method of choice for a woman
who wants to predict fertility based on the length of her cycle. This method does not require the use of a calendar or charting; rather, it uses CycleBeads®.
The SDM, developed at Georgetown University, is the first new natural method of family planning to be clinically tested and introduced on an international scale in over twenty years. To develop the method, researchers used data from the World Health Organization to determine the probability of pregnancy based on the menstrual cycle. Counting the first day of menstruation as day 1, they determined that days 8 to 19 were the most likely fertile window. For SDM, couples avoid having sex during the fertile window.
Who Can Use the Standard Days Method?
The standard days method is most effective for women who have cycles between 26 and 32 days long. It is estimated that it takes about 20 minutes to properly learn to use the standard days method, and it is recommended that you first meet with a trained counselor to be sure you understand this technique before using it.
How to Use the Standard Days Method
To use the SDM you will need to count the days of your menstrual cycle, starting with the first day your period begins.
- Count the first day of your period as day 1.
- On days 1 to 7 you are not fertile and can have unprotected intercourse (provided neither partner has an STD, it is medically safe to have sex even while menstruating).
- On days 8 to 19 you must avoid sex or use a barrier method if you do not want to get pregnant.
- From day 20 until your period starts you can have unprotected sex.
Most women who use this method use special color-coded beads called CycleBeads to help keep track of where they are in their cycles. The figure below shows a set of CycleBeads® used for the standard days method.
Effectiveness of the Standard Days Method
Although the perfect use failure rate is only 5%, the typical failure rate is 12% per year. This rate will be higher for women who have sex during the fertile time, even if using another method of birth control during that interval.
Benefits and Limitations of the Standard Days Method
Because this method is completely natural it addresses the needs of diverse populations with varied religious and ethical beliefs. It also provides an effective alternative for women who want to use natural methods for medical or personal reasons. Other advantages of standard days method include the ease of use, low cost, and complete lack of side-effects and health risks. The standard days method does not offer any protection against sexually transmitted disease.