WASHINGTON, Sept. 20 (UPI) -- A birth control method that shows the 12-day "fertile window" of a woman's period using beads is more effective than a condom, U.S. researchers say.
Victoria Jennings -- a professor of obstetrics and gynecology at Georgetown University Medical Center Institute for Reproductive Health at Georgetown University Medical Center -- said the Standard Days Method identifies the 12-day "fertile window" of a woman's menstrual cycle, taking into account the life span of an egg, 24 hours, and the viable life of sperm, about five days.