A New Bead on Birth Control

To be sure, women who use CycleBeads instead of other methods of natural family planning are sacrificing a certain amount of accuracy for convenience. Methods that depend on extensive self-monitoring and charting can be calibrated to woman's individual cycle. Because CycleBeads depends on playing the averages, it requires more abstaining days than other methods might.

Jennings is frequently asked whether CycleBeads can be customized to a woman's individual cycle: If a woman knows her cycle is exactly 25 days, for example, or can pinpoint her date of ovulation, couldn't she subtract or add beads to make the necklace work better for her?

"We haven't tested that," said Jennings, "so for us, it sort of doesn't exist as a possibility," she said.

The Condom Conundrum

Of course, the big question for CycleBeads users is, what does a couple do if the woman is in her fertile period but they're in the mood? The question is not just hypothetical. A study by Wilcox published last month in the journal Human Reproduction found that the six days of the month when a woman was most likely to have sex are the same six days as her fertile window -- whether or not a couple is planning to conceive a child.

Wilcox suggests that ovulation may be tied to changes in libido or feelings of attractiveness that make intercourse more likely or be linked to increased secretions of pheromones, chemicals though to communicate sexual desire.

"Abstaining during fertile days may be little tougher than you might otherwise suspect," he said.

It's key for couples to develop a strategy for handling their desires during the fertile days, said Jennings, because most unwanted pregnancies among women using CycleBeads come from "oh, what the heck" moments.

"It's chance-taking, mostly," she said, along the lines of, "I know we're on Day 16 of my cycle, but let's just not bother to abstain or use a condom today, let's just take a chance."

Wait, wait. A condom? Isn't this natural family planning? How did a condom get in to the conversation?

It's here that Jennings, and CycleBeads, step onto some delicate political and religious territory. During the "white bead" fertile time, the only instruction that you will find on the CycleBeads product insert is: "Do not have unprotected sex if you do not want to get pregnant." That's because Jennings intends CycleBeads to appeal to a larger audience than simply those who shun contraception on religious grounds -- although she doesn't really want to alienate them, either.