All About Ovulation
What is Ovulation?
Ovulation is the release of a mature egg (ovum) from the ovarian follicle. Each menstrual cycle, several ovarian follicles begin to mature and develop under the influence of pituitary hormones. Usually only one follicle develops fully. While the other follicles recede, this dominant follicle produces an egg which will be released and which can be fertilized. The growing follicle secretes increasing amounts of the hormone estrogen. Following peak estrogen production, there is a surge of luteinizing hormone (LH). The LH surge triggers the release of the mature egg from its follicle. This is ovulation.
The lifespan of the egg after ovulation is just 12-24 hours, maybe even less. Fertilization must take place within this timeframe. After this timeframe, the egg begins to degenerate and is no longer capable of being fertilized. This seems like a very short window of time for conception to take place. However, sperm deposited prior to ovulation can survive in the female reproductive tract for a few days, so the few days before ovulation takes place are also considered fertile days.
and the Cycle Phases
The fertility chart below illustrates the cycle phases with ovulation indicated by the vertical red line.
does Ovulation take place?
A typical menstrual cycle may be anywhere from 21 to 35 days according to the American Society for Reproductive Medicine. Some women even notice cycles that are shorter or longer than this. Ovulation, then, may occur much earlier or later than typical guidelines suggest. For example, ovulation may occur on cycle day 23 during a cycle that is 35 days long for a woman with a 12 day luteal phase while ovulation may occur on cycle day 10 for a woman with a 24 day cycle and a 14 day luteal phase length. This variation among women and from cycle to cycle means that there is really no simple “one-size-fits-all” mathematical formula to calculate your ovulation date. However, it is possible to learn how to identify your own ovulation date and fertile signs by examining your fertility signals.
The chart below illustrates how observing your fertility signs can show you when you are fertile, when you have ovulated, and when to expect your period or a positive pregnancy test result. The ovulation date is indicated by the vertical red line.
To learn more about how to chart your fertility signs and detect ovulation, visit the getting started page.