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Human Blastocyst Biopsy and Vitrification
Published on: July 26, 2019
Blastocyst transfer in frozen-thawed cycles
Ae Ra Han1, Chan Woo Park, Hyoung-Song Lee
1Department of Obstetrics and Gynecology, Kyungpook National University Hospital, Daegu, Korea.
Clinical and Experimental Reproductive Medicine
|October 30, 2012
Summary
Frozen-thawed blastocyst transfer (B-FET) showed no significant difference in pregnancy outcomes compared to cleavage-stage embryo transfer (C-FET). Further large-scale studies are needed to confirm these findings in frozen-thawed embryo transfer cycles.
Area of Science:
- Reproductive Medicine
- Embryology
- In Vitro Fertilization (IVF)
Background:
- Fresh blastocyst transfer generally yields better outcomes than cleavage stage transfer.
- Limited data exists on the efficacy of frozen-thawed blastocyst transfer (B-FET).
Purpose of the Study:
- To evaluate and compare the clinical outcomes of frozen-thawed embryo transfer (FET) using blastocysts versus cleavage-stage embryos.
Main Methods:
- Retrospective analysis of 58 B-FET cycles and 172 age-matched cleavage-stage embryo transfer (C-FET) cycles.
- Comparison also included 22 cycles of extended culture blastocysts from frozen pronuclear stage embryos.
- Patient characteristics, embryo survival rates, implantation rates, and pregnancy rates were analyzed.
Main Results:
- No significant differences were observed in patient characteristics among the groups.
- Embryo survival rates after thawing were high (>90%) and comparable across all groups.
- Implantation rates and clinical/ongoing pregnancy rates did not differ significantly between B-FET and C-FET.
Conclusions:
- Blastocyst transfer in FET may not offer superior pregnancy outcomes compared to cleavage-stage embryo transfer.
- Further large-scale prospective studies are warranted to definitively assess the benefits of B-FET.
