The Effects of Ethanol on Growth and Development of Mouse Two-cell Arrested Embryos

Arresting in a certain step of development, like two-cell stage could be one of the reasons of infertility. In this study, we evaluate the effects of ethanol on growth and development of mouse two-cell arrested embryos. In this experimental study 4-6 week-old female mice were coupled with males following superovulation by intraperitoneal injection of PMSG. Positive vaginal plug mice were killed 48 hours after HCG injection. Two-cell embryos were transferred to RPMI medium; cultured in M16 medium and divided in three groups: 1(control 1), 2 (control 2) and 3(experimental). Second and third groups were exposed to 4 degrees C for 24 hours in order to arrest the two-cell embryos. Group2 were incubated immediately in 38 degrees C, while group3 were exposed to 0.1% ethanol for five minutes and group1 were incubated without any exposure to low temperature. The developmental rate of embryos exposed to low temperature (4 degrees C) were significantly decreased and retarded (P=0.001). There was no significant difference in the mean percent of cleavage rate between groups, but the mean percent of degenerated embryos (P=0.045), morula formation (P=0.005), blastocyst formation (P=0.014) and hatched blastocyst (P=0.001) in 120 h study, were significantly different between groups. The effect of 0.1% ethanol on arrested two-cell embryos can significantly enhance the mean percent of morula formation and development of blastocysts and hatching blastocysts comparing to control group, without any significant effect on cleavage rate.