Aims and Background: Since the birth of the first baby using In vitro fertilization (IVF) in 1978, huge changes have been established in the field of reproductive biology and infertility treatment. Although IVF is considered as a useful technique, but studies have shown that during IVF, some stresses induced by osmosis, oxygen, temperature and pH changes in ectopic conditions can cause morphological, genetic and epigenetic changes in embryos derived from IVF compared to the In vivo. The purpose of this study was to assess the effect of IVF in embryo quality regarding the survival and hatching rates and the expression level of Oct4 and Nanog genes. These genes are effective in the pluripotency of blastocyst inner cell mass.

Materials and Methods: In this experiment 3.5 to 4.5 days old mouse blastocysts were studied in two groups. In treated group, In vitro blastocysts were obtained by passing 100 hours after In vitro fertilization of sperms and oocytes. Fresh blastocysts were also considered as control group. Survival and hatching rates and also Oct4 and Nanog genes expression level were evaluated using Real Time PCR technique in both groups.

Results: Although the hatching rate of blastocysts decreased significantly in treated group (67.73 ± 5.80 vs. 86.88 ± 10.40%), the survival rate was remained 100% as well. In addition Oct4 and Nanog genes expression level was significantly increased in, In vitro blastocyst compared to the control group.

Conclusion: According to the results, in vitro fertilization can change gene expression and quality in the embryo.