Fertility Mythbuster: A woman’s ovulation is the same every month.

Women who ovulate on a regular basis every month may do so on the same day of their menstrual cycle (for example, on day 14 of a 28 day cycle; however, the ovulation is not necessarily the “same” every month.  If the woman has both of her ovaries, she may ovulate from the right ovary or the left ovary in a given month.  Some women with relatively regular menstrual cycles (for example, those with 28-30 day cycles) may ovulate on slightly different day (for example, day 14,15, or 16 depending on cycle length) in a given month than other months, which can be tracked with ovulation predictor kits.

In addition, the quality of the egg that ovulates in a given month may differ from month to month.  A given egg can have either great or poor potential for fertilization by sperm as well as resultant embryo development.  Egg quality cannot be assessed when it is in the body but can be assessed in vitro in the embyrology laboratory during in vitro fertilization (IVF) treatment cycles.