Women who want to get pregnant, as well as those who just as desperately desire the opposite outcome, care a lot about their fertility. But figuring out exactly when to have sex — or when to avoid it — can be tricky.
Using some form of birth control can do the trick, of course, but not all women choose to do so. In theory, natural family planning — knowing when you ovulate to figure out when to have sex — can be useful too. Yet it’s undeniable that more than a few babies (two girls belonging to this author, in fact) have made their way into this world courtesy of mothers who flubbed that calculation.
Now a new study in the October issue of the Journal of Family Planning & Reproductive Health Care finds that a fertility-awareness-based method of family planning developed by researchers from the Institute for Reproductive Health at Georgetown University Medical Center (GUMC) actually works so well for those women who have a pretty regular menstrual cycle that they continued to use it successfully for years.
The Standard Days Method (SDM) zeroes in on the 12-day “fertile window” of a woman’s menstrual cycle. The window accounts for the life span of the woman’s egg — about 24 hours after ovulation — and the five days that sperm remain viable after ejaculation, while allowing for variation between cycles. In the study, which followed 1,659 women who used the method, those who relied on it in the first year were likely to have continued success using it in years two and three.
In 2002, different research found that the SDM was more than 95% effective at avoiding pregnancy, a rate that trumps the effectiveness of other birth-control methods such as the diaphragm or condoms.
It’s unclear what separates the SDM from the more commonly known rhythm method, and perhaps that confusion is part of the reason why natural family planning isn’t more popular. “If you asked 20 people what the rhythm method is, you get 20 different answers,” says Institute for Reproductive Health Director Victoria Jennings, a professor of obstetrics and gynecology at Georgetown. “No one I know actually used the rhythm method partly because it’s never been well-tested for efficacy. People tend to not want to risk that.”
Call it what you want, the concept underlying fertility-awareness birth-control methods is this: a woman ovulates near the middle of her cycle, so she is potentially fertile around that time for several days; adjust the timing of unprotected sex accordingly.
What might contribute to SDM’s success is CycleBeads, a bunch of beads strung on a necklace. Developed at Georgetown, the necklace contains 32 color-coded beads with each bead representing a day of the menstrual cycle. A red bead indicates the first day of a woman’s period; brown beads symbolize days when pregnancy is very unlikely, and glow-in-the dark white beads (beads 8 to 19) signal fertile days. Each day, a woman moves a black rubber ring ahead by one bead to indicate where she is in her cycle.
“It isn’t like it’s this totally radical new concept that no one has ever thought of before, but we have put it into a context that real people can actually use,” says Jennings.
CycleBeads, which costs about $10, does the heavy lifting of figuring out when pregnancy is most likely to occur, says Jennings. “Women need to do math, calculating each cycle and coming up with the days in the current cycle in which she is likely to get pregnant,” says Jennings. “In the Standard Days Method, the calculations have essentially been done for her.”
Women with cycles lasting 26 to 32 days are considered fertile between days 8 and 19. “That gives her a bit of leeway to sometimes ovulate a bit later or a bit earlier and takes into account the life span of egg and sperm,” says Jennings.
One fringe benefit of the beads is enhanced communication between romantic partners. Picture a woman using CycleBeads to demonstrate to her lover where she is in her cycle. “It’s a good tool so they can decide together if they do want to get pregnant, these are the days. Or if they don’t want to get pregnant, they can use the beads to decide when to use condoms.”
CycleBeads are available online, at Whole Foods and in 40 different countries. Lest you bemoan the low-techness of the method, there’s also an app available called “icyclebeads.”