Correlation between in vitro maturation and expression of LH receptor in cumulus cells of the oocytes collected from PCOS patients in HCG-primed IVM cycles

BACKGROUND: The aim of this study was to investigate whether in vitro maturation (IVM) and blastocyst development of oocytes collected following HCG-primed IVM cycles of PCOS patients are correlated with their cumulus cell (CC) patterns and further to investigate mRNA expression of the receptors for FSH, LH and epidermal growth factor (EGF) in the CCs with each pattern. METHODS: Patients who underwent IVM were primed with 10 000 IU of HCG 36 h before oocyte aspiration. The isolated cumulus-oocyte complexes were divided into three groups according to the CC patterns: oocytes with dispersed CCs (group A), oocytes with compacted CCs (group B) and oocytes with sparse CCs (group C). Oocyte maturation and blastocyst development were compared among three groups. The expression of the mRNA for FSH, LH and EGF receptors in group A and B was analysed by semi-quantitative RT-PCR. RESULTS: The maturation rate of group A was significantly higher than those of group B and C. The rate of blastocysts in group A was significantly higher than those of group B and C. mRNA expression of the LH receptor in group A was more abundant than that of group B. CONCLUSIONS: These results suggest that the presence of dispersed CCs at oocyte collection may be positively correlated with the rates of oocyte maturation and blastocysts in HCG-primed IVM cycles. In addition, the expression of LH receptor in CCs may be correlated with the CC pattern of oocytes at collection.