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Updated: Oct 3, 2026
The Immediate Partial Removal of Cumulus-Oocyte Complexes: A Refined Approach for Rapid Observation of In Vitro Fertilization
Published on: October 18, 2024
Birth of healthy twins from in vitro development of human refrozen embryos
1Yokota Obstetrics and Gynecology Clinic, 1-16-5 Shimokoide, Maebashi, Gunma 371-0031, Japan. yaaraki@mb.infoweb.ne.jp
Objective:
To avoid the risk of ovarian hyperstimulation syndrome and promote pregnancy rate by freezing pronuclear embryos at the oocyte retrieval and using developed refrozen supernumerary embryos in the event of failed pregnancies.
Design:
A case study.
Setting:
Private IVF center.
Patient(S):
Healthy infertile woman undergoing IVF treatment.
Intervention(S):
Slowly frozen and rapidly refrozen embryos at varying stages of embryonic development were transferred.
Main Outcome Measure(S):
Survival rate of refrozen and thawed embryos; safety of refrozen embryo transference.
Result(S):
Fertilized pronuclear embryos that were frozen, thawed, and developed to morula embryos were subsequently vitrified, rethawed, and cultured until blastocyst formation before transfer. Healthy fraternal twins were born by caesarian section. The result of transfer was the novel finding of a successful delivery after the use of refrozen embryos.
Conclusion(S):
The transfer of refrozen supernumerary embryos resulted in successful pregnancy and delivery. We will continue to investigate the safety and efficacy of the elective freezing of all embryos as well as their refreezing so that supernumerary embryos can be reused to avoid ovarian hyperstimulation syndrome or in cases of repeated failed pregnancies.
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