Implantation window

The human endometrium changes shape dramatically every day after ovulation. As a result, we can perform histopathological examination called "endometrium date diagnosis" that estimates whether or not the endometrium is receptive at the expected time.
The endometrium is biopsied with a special instrument for this test.
In the endometrial date examination, a delay of 2 days or more must be accommodated for.
However, the result of the date examination often depends on the site where the biopsy is collected and the judgment of the observer.
It is not uncommon for pregnancy to be established in the next cycle even if it is delayed in the previous cycle.
Recent studies suggest that the over-advanced endometrium cannot accept an embryo any more than under-advanced.
If the advancement continues for 3 days or more, it may be impossible to establish a pregnancy.
(Papanikolaou EG, et al. Reproductive Biomedicine Online. 2010; Vol 21: p50-55. )
Preventing and treating this situation is a problem we wish to solve.