PINOPODE FORMATION IN HEALTHY OOCYTE DONORS IN THE CYCLES OF CONTROLLED OVARIAN HYPESTIMULATION

The problem of endometrial receptivity remains to be one of the most actual in the field of human rep-roduction. The embryo can implant during the narrow period called the ?implantation window? which is cha-racterized by formation of pinopodes. The aim of this study was to evaluate the pinopode formation in healthy oocyte donors in the cycles of controlled ovarian hypestimulation (COH). The objects of investigation were 20 healthy oocyte donors. The pinopodes in the endometrial biopsies were investigated with scanning electron microscopy. In the majority of the cases (13-65%) developed pinopodes were found on LH+6 and LH+7, in 7 women (35%) ? on LH +8 ? LH+10. In repeated COH cycles in the same women the developed pinopodes were seen on the same days in 5 (from seven) cases and with 1-day difference in 2 cases. In COH cycles pinopodes appear on the LH+6 ? LH+10 days; in the majority of cases the developed pinopodes are seen on LH+6, LH+7; the time of pinopode formation is mainly constant in the same woman under the same conditions; COH does not influence the time frames of pinopode formation.