Figure 1.

Scanning electron microscopy photomicrographs of luminal surface of human endometrial biopsies were taken from proliferative (A), early (B), mid- (C) and late luteal (D) phases of normal menstrual cycle to identify developmental stage of pinopodes. Notice that there are not any pinopodes in proliferative phase, few isolated pinopodes are detectable in specimens from early luteal phase, numerous developed pinopodes are detectable in the mid-luteal phase, and regressive pinopodes are dominant in late luteal phase specimens. Scale bar = 5 µm.