Endometrial receptivity. Homo sapiens

In GnRH-antagonist/rec-FSH stimulated cycles, advanced endometrial maturation on the day of oocyte retrieval correlates with altered gene expression Keywords: gene expression analysis, advanced endometrial maturation Overall design: Endometrial biopsies taken on the day of oocyte retrieval in stimulated IVF cycles with 1 or 2 embryos replaced on day 3 in the same cycle. Endometrial dating was performed according to Noyes' criteria. All endometria taken on the day of oocyte retrieval showed an advanced maturation, ranging from +d2 to +d4. The patients with a subsequent clinical pregnancy all showed a histological dating corresponding to +d2 or +d3. Gene expression of histologically more advanced endometria, as assessed by Noyes' criteria, (n=3, +d4) was compared with matched less advanced endometria (n=4,+d2-3).