Secretory endometrium dating
In the most common terminology for dating the endometrial biopsy, day 1 is used as the first day of bleeding, and this is used in Fig. Endometrial cycle length is often described as an idealised 28 days in duration, but this may be slightly longer or shorter even in normal women.These physiologic variations occur in the preovulatory phase, as tight programming of postovulatory events fixes the postovulatory interval at about 14 days.
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.Steroid hormone control of endometrial, epithelial, stromal, and presumably endothelial cells is mediated by estrogen receptors and progesterone receptors. They have high affinity to bind estradiol and progesterone, respectively.