Clinical efficacy analysis of oocyte cryopreservation: A propensity score matched study

Objective To investigate the effectiveness of oocyte thawing cycles in the clinical application of assisted reproductive technology (ART). Study design The clinical data of 78 cases who underwent oocyte thawing cycles in our center were retrospectively analyzed. All patients in this study received oocyte cryopreservation for the husband reason. According to patient age at egg freezing, patients were divided into three observation groups (Group A, <30 years old; Group B, 30-34 years old; Group C, >= 35 years old), and the control groups were selected by propensity score matching with fresh cycles. The clinical outcomes of each group were compared, and the clinical efficacy of oocyte thawing cycles was analyzed. Results Clinical pregnancy outcomes of oocyte thawing cycles were not significantly different from that of fresh oocytes, but vitrification affected the number of two pronuclei zygotes developing to cleavage stage and the number of high-quality embryos, and the normal fertilization rate after thawing. The cycle cumulative live birth rate in Group C was significantly lower than those in Groups A and B. The live birth rates per egg of Groups A, B, C were 5.03%, 5.61%, and 3.57%, respectively, and the numbers of eggs per live birth were 13.72, 14.43, and 21.0, respectively. Conclusions The overall clinical outcomes of oocyte vitrification were similar to that of fresh oocytes, but the cleavage rate and embryo quality of frozen oocytes were slightly reduced. Freezing of oocytes in women over 35 years of age affects the clinical efficacy of ART.