Expression data from cumulus cells that surround oocytes resulting in early or late cleaving embryos

Besides the established selection criteria based on embryo morphology and blastomere number, new parameters for embryo viability are needed to improve the clinical outcome of in vitro fertilization (IVF) and more particular of elective single embryo transfer (eSET). The aim of the study was to analyse genome-wide whether the embryo viability was reflected by the expression of genes in the oocyte surrounding cumulus cells. Early cleavage (EC) was chosen as a parameter for embryo viability. Keywords: class comparison Consenting patients visiting the IVF clinic underwent an IVF or ICSI treatment. Immediately following ultrasound-guided cumulus-oocyte-complex (COC) retrieval, a proportion of the cumulus cells surrounding the oocyte were removed. Gene expression in cumulus cells from eight oocytes resulting in an early cleavage embryo (EC-CC; n=8) and from eight oocytes resulting in a non-EC embryo (NEC-CC; n=8) derived from six patients were analysed using microarrays (n=16). To exclude a differential gene expression due to differences in patient characteristics, samples were paired. From four patients both an EC-CC and a NEC-CC sample were used. From two additional patients two EC-CC as well as two NEC-CC samples were used.