Prospective controlled study to evaluate laboratory and clinical outcomes of oocyte vitrification obtained in in vitro fertilization patients aged 30 to 39 years.

OBJECTIVE: To determine whether the process of oocyte vitrification affects oocyte viability in in vitro fertilization (IVF) patients between 30 and 39 years of age.
DESIGN: Prospective controlled study.
SETTING: Private IVF practice. PATIENT(S): A total of 30 women assigned and 22 qualified. INTERVENTION(S): Denudation of oocytes, cryopreservation of oocytes using vitrification method in a medium with 15% ethylene glycol (EG), 15% dimethylsulfoxide (DMSO), and 0.5 M sucrose. MAIN OUTCOME MEASURE(S): Oocyte survival, fertilization, day-3 embryo quality, blastocyst formation, clinical pregnancy, implantation, and live-birth rates. RESULT(S): After denudation of oocytes, mature sibling oocytes were randomly allocated to the fresh and vitrified groups. The survival rate was 79.6% after vitrification/warming. Overall, no statistically significant differences were found in fertilization, day-3 embryo quality, or blastocyst formation rates between the fresh and vitrified groups. The positive β-human chorionic gonadotropin, clinical pregnancy rate, and implantation rate were 13 (59.0%) of 22, 10 (45.4%) of 22, and 16 (30.1%) of 53 for the vitrified group. The overall efficiency in achieving a live birth was 11 (5.9%) of 186 per vitrified oocyte. CONCLUSION(S): The impact of vitrification can be reduced to a minimal level, making it possible to achieve high pregnancy and implantation rates in this age group of IVF patients.