In addition to the protein marker of endometrial receptivity, we also observed the pinopodes, which are smooth mushroom-like projections that arise from the apical surface of the endometrium and are considered as endometrial receptivity marker .
Loutradus et al., "Implantation: uterine pinopodes as markers of the 'nidation window' in cycling women receiving exogenous oestradiol and progesterone," Human Reproduction, vol.
on luminal epithelium were confluent; glands secretion and stromal edema were well developed during WOI (b) compared to the prereceptive phase (a).
We hypothesize that the endometrial receptivity was significantly reduced after COH  and that pinopodes emerge prematurely, leading to early opening of the implant window .
Bentin-Ley, "Relevance of endometrial pinopodes for human blastocyst implantation," Human Reproduction (Oxford, England), vol.
Pinopodes, coming with the loss of microvilli on the surface of endometrial epithelium, are large, rounded, and smooth-surfaced projections of the apical plasma membrane.
We found a significant disappearance of the pinopodes on the surface of the mice endometrial epithelium after exposure to X-irradiation.
Presence of uterine pinopodes
at the embryo- endometrial interface during human implantation in vitro.
In mice lacking of LIF, absence of pinopodes
was observed .
indicate a shift in the window of receptivity in IVF cycles.
The endometrial epithelium has a highly specific appearance: Microvilli, which are present after ovulation, disappear six days after ovulation; the cells are then covered with pyramidal protrusions called pinopodes
, which disappear, in turn, nine days after ovulation.
Immunohistochemical assay, real time polymerase chain reaction (RT-PCR) assay, TUNEL method, biomarkers associated with endometrial receptivity such as endometrial thickness, angiogenesis, and pinopodes
by microscopic examination were measured by microsocpic exam.