No 'multiple ovulations'.

Erroneous news reports that women can ovulate more than once during a menstrual cycle resulted from journalists' misinterpretation of a study published in the July 2003 issue of the journal Fertility and Sterility, reproductive health experts say.

The experts have responded to news reports about the study that had misleading headlines such as "No 'safe' time to avoid pregnancy." Jeff Spieler, chief of the research division of the U.S. Agency for International Development's Office of Population and Reproductive Health, calls this claim "a total fabrication" that raised unfounded doubts about the efficacy of natural family planning (NFP) methods and oral contraceptives.

In the study, researchers at the University of Saskatchewan in Saskatoon, Canada, tested whether ovarian follicles develop in "waves" in humans, as they do in some animals. A competing hypothesis held that follicles grow only during the first half of a woman's menstrual cycle, until hormones induce one follicle to release an egg.

The researchers observed two to three waves of follicular development during a typical menstrual cycle in 50 women who received daily sonograms. During each wave, a few follicles grew larger than the rest, and one outgrew the others. In each woman, however, only one wave resulted in ovulation.

During the waves that did not result in ovulation, some follicles grew to "an ostensibly pre-ovulatory diameter," the researchers note. "It could, therefore, be speculated," they write, that these follicles could ovulate in the presence of a surge of luteinizing hormone. News reports described this speculative potential for "multiple ovulations" as if they had actually occurred and questioned the efficacy of natural family planning methods requiring accurate estimates of the days when a woman is fertile.

"NFP will not fail because of a second fertile period or secondary ovulation in the same cycle," says Spieler, who has conducted studies on ovulation. "Hundreds of ultrasound studies have been done, and there is no evidence for a second follicle developing to the size of one that will rupture and release another egg later in the same cycle."

In fact, notes Dr. Marcos Arevalo, director of biomedical research at the Institute for Reproductive Health at Georgetown University in Washington, DC, the study's "data on the day of ovulation, and the fact that actual ovulation occurs only once in a cycle, provide support for the efficacy of natural family planning methods."

News reports also suggested that "multiple ovulations" would put some women at risk of unplanned pregnancy during the seven days when they take the placebo pills in a pack of oral contraceptives. "This is simply not true," Spieler says. "Women may wish to switch to a continuous regimen of active pills for other reasons, such as avoiding menstruation, but there is no evidence that they are not protected from pregnancy during that pill-free week."