Comparison of the effects of three commercial media on preimplantation mouse embryo development and morphological grading.

Embryo culture is a vital procedure in Assisted Reproductive Technologies (ART). Assessment of embryonic morphology and development is of importance in the selection of embryos for transfer. Survivability of embryos in culture media depends on nutrient supply to maintain embryonic growth at every stage of preimplantation development. The objective of this study was to observe the effect of M16, HTF and KSOM commercial media on preimplantation embryonic development and morphological grading. Female mice were superovulated with pregnant mare's serum gonadotropin (PMSG) followed by human chorionic gonadotropin (hCG) 48 h later. The oviducts were flushed at 23 -25 h post-hCG using M2 medium. Embryos with two pro-nuclei were selected for culture. A total of 240 embryos were equally divided for culture in M16, HTF and KSOM media. Embryonic development and morphological grading were observed at 48, 67, 74, 93 and 11 h post-hCG until the hatched blastocyst stage. Significantly higher numbers of blastocysts was observed in HTF and KSOM cultures at 93 h post-hCG, compared to M16 culture (p<0.05). HTF showed a significantly higher number of Grade B4 blastocyst (p<0.05), while KSOM showed a significantly higher number of Grade B1 blastocysts (p<0.05), compared to M16. Morphological quality appeared to be stage dependant. M16 medium showed significantly higher number of 8-cell stage (n=62) compared to HTF (p=0.026). Our observations suggested that for ICR mouse embryos, M16 is effective in promoting pre-compaction stage development until the 8-cell stage, while HTF and KSOM were more effective in promoting post-compaction stage development, hence producing more blastocysts.