ABSTRACT
RESEARCH QUESTION: Does double stimulation (DuoStim) affect cumulus cell gene expression in luteal-phase-derived oocytes? DESIGN: This prospective observational study included 39 patients with reduced ovarian reserve. Fifteen patients (group 1) underwent IVF with a gonadotrophin-releasing hormone antagonist in the follicular phase and 24 patients (group 2) underwent DuoStim. A total of 149 cumulus cell samples were divided into two groups according to the phase of the cycle: group 1 included 55 follicular-phase-derived oocytes and group 2 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 cumulus cells was similar between DuoStim luteal-phase-derived oocytes and follicular-phase-derived oocytes. A significant increase in the mRNA levels of VCAN (15.542 ± 6.8 versus 20.353 ± 10.58; Pâ¯=â¯0.001), SDC4 (1.016 ± 0.65 versus 1.318 ± 0.97; Pâ¯=â¯0.013), and TP53I3 (0.185 ± 0.09 versus 0.270 ± 0.11; Pâ¯=â¯1.19E-05) was observed in group 2. The number of oocytes collected (5.57 ± 2.3 versus 5.7 ± 2.7; P > 0.05) and the number of blastocysts were comparable between the groups (2.1 ± 2.1 versus 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, SDC4, and TP53I3 in the cumulus cells of luteal-phase-derived oocytes. These results, however, did not correlate with oocyte maturation, embryo quality and pregnancy rate.
