Multiple Follicular Stimulation, Secondary Fertility, and the Purple Box

When the vaginal sensor is used in conjunction with the oral sensor, the OvaCue® tracks changes in the electrolyte levels in your cervical mucus, which allows the monitor to detect the switch from estrogen to progesterone dominance that accompanies ovulation. When this shift occurs, you will see an increase in the vaginal readings (called the Vaginal Rise) and a pink square will appear on your monitor’s calendar.  Typically, the appearance of the pink square confirms ovulation and signals the end of your fertile window.  After ovulation, the vaginal readings will typically remain high, reflecting the high levels of progesterone that are present during the luteal phase of the menstrual cycle. 

After the pink box has been displayed, if the OvaCue® detects a dip in your vaginal readings, and then a subsequent rise in your vaginal readings, the monitor will display a purple box. The appearance of this purple box simply suggests that your vaginal readings for the current cycle did not follow the typical pattern of remaining elevated following ovulation. 

One possible explanation for this unusual pattern in the vaginal readings is "Secondary Fertility", a term used to explain the elongation of the fertile window due to multiple follicular stimulation.   If you see a purple box during a cycle, it is important to look back at trends in your oral readings to see if you can identify a second Cue Peak (a high oral reading followed by two lower oral readings). This second "Cue Peak" (which would have occurred 5-7 days prior to the purple box day) may indicate that a secondary follicle was selected, perhaps due to the inability of the dominant follicle to mature and/or rupture.  A secondary Cue Peak in conjunction with a secondary vaginal rise (displayed with a purple box) is a solid indicator that you experienced multiple follicular stimulation.  For subsequent cycles it will be important to continue taking vaginal readings throughout the entire luteal phase of your cycle so that you can identify this trend in your vaginal readings.  It will also be important to remember that your fertile window might extend beyond the pink box, and that you should continue to try to conceive until a purple box is seen or your calendar returns to white. 

For more information or assistance please contact us.