The information below explains SDM and how it is different from the rhythm method: http://www.cyclebeads.com/FAQ/
Q. What is the Standard Days Method?
A. The Standard Days Method is a new, simple method of family planning that was developed by the Institute for Reproductive Health at Georgetown University. The Institute developed a computer model, based on data from the World Health Organization, and determined that women who usually have menstrual cycles between 26 and 32 days long are potentially fertile – or able to get pregnant – on days 8 through 19 of their cycles. So the Standard Days Method identifies a fixed set of days in each menstrual cycle as the days when a woman can get pregnant if she has unprotected intercourse. If the woman doesn’t want to get pregnant, she and her partner avoid unprotected intercourse on days 8 through 19 of her cycle. The Institute has tested the Standard Days Method in a clinical trial with about 500 women in 3 countries – Bolivia, Peru and the Philippines. They found that women were able to use the method correctly, and when they did use it correctly, it was more than 95% effective. That is, out of 100 women using the method for 1 year, fewer than 5 would get pregnant.
Q. How is this different from the rhythm method?
A. Actually, it’s very different. The rhythm method involves having exact information about the last 6 menstrual cycles and every month making complex calculations – adding and subtracting – to figure out which days in the current cycle you’re likely to get pregnant. And the rhythm method has never actually been tested in a well-designed efficacy study. The Standard Days Method on which CycleBeads are based, is simple – it doesn’t involve any calculations, and it is the same every cycle. It has also been tested in a well-designed effectiveness trial, with excellent results.
BTW, I successfully charted with the symptothermal method for awhile before conceiving my first DD and before my second DD. Now with two kids I'm simply looking for an easier way of keeping track, because I have trouble committing to temping. I have had success with the mucus only method, but I am now considering using cycle beads because, though my cycles fluctuate, they do fall between the 26-32 day range. It seems this could be a good system for those with somewhat regular cycles, especially if you are also aware of your cm to alert you to any irregularities.
Thoughts?
