These critera were used in 300 sterility biopsies taken from normally menstruating women over a 3-year period.
Absence of organic endometrial disease and availability of accurate menstrual history were the only selection criteria. 42 of the 300 patients (14%) menstruated on the day predicted, 36 (12%) menstruated later, and 222 (74%) menstruated earlier.
In any case, one should not average cycle days and report ’POD 3 or 17th-day secretory endometrium’.
Endometrial biopsies are not to be taken at the onset of bleeding in the following two conditions: if luteal phase defect (LPD) is suspected clinically and is desired to be confirmed histologically, when the biopsy should be taken between POD 7 (21st) and POD 9 (23rd) cycle days to demonstrate a 3–4 day delay in endometrial maturation; or if there are asynchrony of gland/stromal development and dissimilar maturation in different regions of the endometrial specimen.
In LPD, circulating progesterone levels are decreased and not sufficient to promote full secretory differentiation of the endometrium.