New research suggests that you can ovulate twice in one month.
More Info: That’s what a new study published in the journal Fertility and Sterility is claiming. The study, led by Dr Roger Pierson, director of the reproductive biology research unit at the University of Saskatchewan, found that women can potentially ovulate two or even three times in one month. According to the researchers, if this theory is confirmed, the textbooks will have to be rewritten.
When a woman ovulates, the pituitary gland releases a follicle-stimulating hormone (FSH) that prompts 15-20 follicles to begin to grow in the ovaries. Once one egg has matured sometime during the middle of the cycle, it releases estrogen, which signals the pituitary gland to release Luteinizing hormone (LH), which triggers the release of the egg into the fallopian tubes. The remaining eggs deteriorate.
The Ovulation Study
This new research suggests that this may not be the end of the story. The study, published in the 2003 journal Fertility and Sterility, set out to test the hypothesis that folliculogenesis occurs in a wave-like fashion by evaluating changes in ovarian follicle dynamics during the menstrual cycle
In the study, the researchers performed daily ultrasounds on 50 women between the ages of 19-43, with a history of regular menstrual cycles that did not take any medications known to interfere with reproductive function.
The researchers found that all of the women produced at least two waves of follicle growth–sixty-eight percent of the women exhibited two waves of follicle development and thirty-two percent exhibited three waves.
What Does This Mean?
In an article covering the findings published in the British Medical Journal, Dr. Pierson said that 40% of the women had the biological potential to produce multiple eggs in a single month and further could be fertile at any time during the month. He goes on to say that these findings could explain why the rhythm method of family planning often fails and fraternal twins that have different conception dates.
Because current scanning methods can detect follicles but not the actual egg, it is not definitive if any of the women actually ovulated twice.
Baerwald AR; Adams GP; Pierson RA; Fertility and Sterility
A new model for ovarian follicular development during the human menstrual cycle
2003; Volume: 80; No: 1; pp: 116-22
Dyer, Owen; British Medical Journal
Women may ovulate two or three times a month
2003; Volume: 19; No:327; pp:7407