Fertility research findings surprise many doctors

By JANE E. ALLEN
LOS ANGELES TIMES
Women ovulate once a month. Couples' lives, their choice of contraception and even their efforts to combat infertility have been based upon this well-established biological notion. But some researchers say it may not be as ironclad as we've thought.
Canadian scientists have found that a few women ovulate twice a month, and others have the biological potential to do so.
The discovery might explain why some women who rely on natural family planning methods and others who conscientiously take oral contraceptives still become pregnant, said lead study author Roger Pierson, director of reproductive biology research at the University of Saskatchewan. There may be no "safe" time during their menstrual cycles, he said.
Reproductive specialists have long theorized that a group of egg sacs, called follicles, begin growing inside the ovary at the beginning of each menstrual cycle. According to that theory, one follicle fully matures, bursts open and releases an egg around the 14th day of a 28-day cycle.
But the researchers, who tracked activity inside the ovaries with daily ultrasound testing, found that two or three times a month groups of follicles enlarge and one follicle sometimes matures until it is on the verge of releasing an egg. Most of the 63 women studied released an egg just once a month but, in six cases, eggs were released twice. The waves of follicle development occur in healthy women who have a single menstrual period each month, the scientists said.
The finding suggests that given sufficient hormonal stimulation, or if a woman takes medications known to disrupt the hormones that govern ovulation, mature eggs might be released at more than one point in a woman's cycle, Pierson said.
But several leading infertility specialists said the discovery might not make much difference.
"Hormonal stimulations have been tried at various times of the menstrual cycle through trial and error," said Dr. Thomas Toth, director of the in vitro fertilization program at Massachusetts General Hospital in Boston. The greatest successes have come with stimulating the ovaries in the first half of the menstrual cycle, he said.