RESUMO
BACKGROUND: The alteration in microfilaments of human oocytes by vitrification has not been understood well. OBJECTIVE: To evaluate the effect of vitrification on the microfilaments of human in vitro matured oocytes and the time needed for the repair. MATERIALS AND METHODS: Human in vitro matured oocytes were divided into the control group (Group 1) and the vitrified group. The vitrified oocytes were further divided into four sub-groups that were cultured after thawing for 1 h, 2 h, 3 h and 4 h, respectively (Groups 2, 3, 4 and 5). RESULTS: The survival rate of oocytes was 87.4% after vitrification and thawing. The percentage of oocytes with a normal configuration of microfilaments in Group 2 and Group 3 was significantly lower than that of the fresh control group (Group 1), whereas the percentage of oocytes with normal microfilament configuration in Group 4 and Group 5 was comparable to the control group. CONCLUSION: Vitrification alters microfilament structure of oocytes, which takes at least 3h after thawing for the repair and recovery.