Ovulation and Fertile Window (what they are)

Ovulation:

The time when one of the two ovaries releases an egg. When ovulation occurs, the mature egg is released from its protective follicle in the ovary. This process of follicular rupture looks a bit like a small volcano erupting on the ovarian surface. At this time, the tubal fimbria, like tentacles, sweep over the surface of the ovary and actually “swallow” the egg into the tube. The egg then has a few hours lifetime (8 to 12 hours or maybe up to 24 hours) in the protective confines of the fallopian tube, for a sperm to swim up and reach it.

Fertile phase or fertile window:

The days of the menstrual cycle, during which sexual intercourse or insemination may result in pregnancy. It includes several days leading up to and including ovulation. The exact number of the fertile days is not known. It is currently believed (due to a poorly designed but influential study published and promoted in 1995) to be 6 days. That’s rather than 3 days, although evidence shows that there are only 3 days of high probability of conception – while the other three days are likely due to the inadequate methods of ovulation monitoring used in all those earlier studies.

The fertile window is an empirical factor, which should be consistent with the fertilizable lifetimes of the gametes (the egg and the sperm). Those are also uncertain but currently accepted figures are up to 12 (or maybe 24) hours for the egg, and at most 3 days for the sperm. The unequivocal determination of the fertile window is a pivotal task for bioZhena (a large pre-launch clinical trial).