CUMULUS CELL GENE EXPRESSION IN LUTEAL PHASE-DERIVED OOCYTES AFTER DOUBLE STIMULATION IN ONE MENSTRUAL CYCLE

ABSTRACT Research question Does double stimulation (DuoStim) affect cumulus cell (CC) gene expression in luteal phase-derived oocytes? Design This prospective observational study included 39 patients with reduced ovarian reserve. Fifteen patients (Group I) underwent in vitro fertilization with a gonadotropin-releasing hormone antagonist in the follicular phase and 24 patients (Group II) underwent DuoStim. A total of 149 CC samples were divided into two groups according to the phase of the cycle; group I included 55 follicular phase-derived oocytes and group II included 94 luteal phase-derived oocytes. The expression levels of the following genes were assessed using quantitative polymerase chain reaction: HAS2, VCAN, ALCAM, PTGS2, GREM1, ITPKA, TRPM7, SDC4, CALM2, SPSB2, TP53I3, PGR, and PFKP. Results The expression of 10 out of 13 genes in CCs was similar between DuoStim luteal phase-derived oocytes and follicular phase-derived oocytes. However, a significant increase in the mRNA levels of VCAN (15.542±6.8 vs. 20.353±10.58, P = 0.001), SDN4 (1.016±0.65 vs. 1.318±0.97, P = 0.013), and TP53I3 (0.185±0.09 vs. 0.270±0.11, P 0.05) and the number of blastocysts were comparable between the groups (2.1±2.1 vs. 2.7±2.2, P>0.05). Conclusions The DuoStim approach leads to changes in the follicular environment. It affects the expression levels of VCAN, SDN4, and TP53I3 in the CCs of luteal phase-derived oocytes. However, these results did not correlate with oocyte maturation, embryo quality, and pregnancy rate. Study funding/competing interest(s) None Trial registration number N/A.