ABSTRACT
Objective The embryonic development is usually observed for 5-6 days during the process of embryo culture in most embryonic laboratories.The article aimed to explore the application of D 6+D7 frozen-thawed blastocyst transfer in patients with di -minished ovarian reserve(DOR). Methods Retrospective analysis was conducted on 285 patients with DOR who were treated with in-vitro fertilization and embryo transfer (IVF-ET) in our center from 2015 to 2017.Frozen embryos were harvested from the natural cycle , mini-stimulation protocol, ovulation induction during the luteal phase , followed by frozen-thawed embryo transfer with a total of 442 cycles. The frozen embryos were divided into cleavage embryo group and blas -tocyst group according to different life stages , and comparison was made in general data and pregnancy outcome between the two groups .The blastocyst transfer group was subdivided into Day 5 group and Day6+Day7 group followed by the comparison of different pregnancy outcome between the two groups . Results Patients with DOR were treated with frozen-thawed blastocyst transfer with 291 cycles in cleavage embryo group and 151 cycles in blastocyst group.The implantation rate, clinical pregnancy rate, and ongoing pregnancy rate of blastocyst group were significantly higher than those of cleavage embryo group ( 44.62％ vs 22.46％, 50.33％ vs 33.33％, 37.75％ vs 21.65％, P<0.05) and the abortion rate of blastocyst group was significantly lower than that of cleavage embryo group (35.05％ vs 25％, P<0.05).As to the frozen blastocyst transplantation cycle , the number of D5 blastocysts was 69, and D6+D7 blastocyst was 76. The embryo planting rate, clinical pregnancy rate, continued pregnancy rate and abortion rate of D 6+D7 group were higher than those of D5 group(39.74％ vs 50％, 44.93％ vs 55.26％, 34.78％ vs 39.47％, 22.58％ vs 28.57％), but the difference was of no statistical significance(P>0.05). Conclusion In patients with DOR, the transplanted blastocyst can significantly improve the pregnancy out -come, increase the clinical pregnancy rate and reduce the abortion rate .The embryo planting rate and clinical pregnancy rate of the transplanted D6+D7 blastocyst were higher than those of D 5 blastocyst, but the difference was not statistically significant .The abortion rate was also increased.Therefore, when the number of embryos is limited, patients with DOR may consider transplanting D 6+D7 high-quality blastocysts in order to get a certain clinical pregnancy rate .
ABSTRACT
OBJECTIVE: This study conducted a preliminary examination of the effects of three-area laser-assisted zona thinning (LAZT) during the cleavage stage of embryo development on the hatching process in human in vitro fertilization-embryo transfer (IVF-ET) with subjects of advanced female age or frozen-thawed (FT) embryos. METHODS: Eight-cell stage embryos were treated with LAZT in three areas of the zona pellucida at 120° intervals. The control group was embryos without LAZT. Of the 72 consecutive fresh cycles and the 28 FT embryo transfer cycles, the patients in 55 fresh cycles and 17 FT cycles declined LAZT, and those cycles were defined as the control group. RESULTS: In the fresh cycles, the pregnancy rates were similar in the LAZT and control groups. However, in the FT cycles, the pregnancy rate was significantly higher in the LAZT group than in the control group (45.5% in the LAZT group vs. 23.5% in the control group, p < 0.05). CONCLUSION: These results show that multi-area LAZT resulted in significantly improved pregnancy outcomes in human 8-cell embryos compared to controls.