The new natural method of family planning, called the Standard Days Method, is more than 95 percent effective at preventing pregnancy, its developers said at a news conference.
Funded by the US Agency for International Development, the Institute for Reproductive Health at the Georgetown University Medical Center, developed and tested the simple, low-cost method in clinical trials on 478 women in Bolivia, Peru and the Philippines.
The crux of the SDM is a strand of color-coded CycleBeads, a necklace-like visual reminder that allows a woman, and her partner, to identify the fixed fertile window in her menstrual cycle when she can become pregnant. Each bead represents one day of a woman’s menstrual cycle, with different colored beads to indicate fertile and infertile days.
To use the CycleBeads, a woman moves a rubber ring over one bead every day to visibly track where she is in her cycle. Day 1 of the cycle, which is her first day of menstrual bleeding, is represented by a red bead, followed by six brown beads. The days 8-19 of the cycle are represented by white, phosphorescent beads. Women are counseled to avoid unprotected intercourse when the rubber ring is located on the white beads.
The SDM, for women whose menstrual cycles usually last between 26 and 32 days, differs from the rhythm method in that the rhythm method requires that the woman collect detailed information about the last six menstrual cycles and perform monthly calculations to figure out which days in the current cycle she is most likely to get pregnant.
Use of this method is likely to prove popular, especially in countries like the Philippines where widespread use of artificial contraceptives is curtailed by cultural and religious beliefs.
The clinical trials in the Philippines began in November 1999 and involved 203 women in two localities in Tuba and La Trinidad in Benguet. Health workers followed them for 13 cycles and reported "very, very few women left the study because they did not like it."
Jennings said the acceptance of this method of contraception in the Philippines was so overwhelming that "we had to turn out so many women who wanted to participate in the test." Generally the beads are free but in certain areas they are sold for P50 each.
"There was so much interest and demand for CycleBeads that many women, even if they were not included in the test sample used the beads," she said.
According to studies by reproductive health professionals, more than 60 million women worldwide report using "periodic abstinence" to avoid pregnancy but the vast majority of them do not know when they are most likely to get pregnant.
The Washington-based Population Reference Bureau says the reasons for not using contraception range from fears of the side-effects of contraceptive methods, religious belief, to family pressure to have more children.
She said the Department of Health in Manila was very supportive of the project and issued an administrative order in 2001 saying that since the method had proven to be effective, it could be offered to all women.
"The reason it is not being offered nationwide yet is because we need to set up logistics, train midwives and have more beads available," Jennings said.
The study found the efficacy of the Standard Days Method to be comparable to or better than a number of other widely used methods of family planning, including the diaphragm and condom.
Since the clinical trials in Bolivia, Peru and the Philippines, the SDM has been introduced in Benin, El Salvador, Ecuador, Guatemala, Honduras, India, Mexico, Nicaragua and Turkey.