1. Cumulative live birth rate in freeze-all cycles is comparable to that of a conventional embryo transfer policy at the cleavage stage but superior at the blastocyst stage
- Author
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Francesca Pennetta, Andrea Borini, Antonia Bazzocchi, Carlotta Zacà, M.A Bonu, and Giovanni Coticchio
- Subjects
0301 basic medicine ,Adult ,Cleavage Stage, Ovum ,Oocyte Retrieval ,Cryopreservation ,Andrology ,Cohort Studies ,03 medical and health sciences ,0302 clinical medicine ,Ovulation Induction ,medicine ,Clinical endpoint ,Humans ,Blastocyst ,Stage (cooking) ,Birth Rate ,Retrospective Studies ,030219 obstetrics & reproductive medicine ,business.industry ,Obstetrics and Gynecology ,Embryo ,Embryo Transfer ,Embryo transfer ,030104 developmental biology ,medicine.anatomical_structure ,Reproductive Medicine ,Female ,business ,Live birth ,Cohort study - Abstract
Objective To determine whether the freeze-all policy ensures a higher efficacy in terms of cumulative live birth rate (CLBR) in comparison with a conventional fresh/frozen embryo transfer (ET) approach in patients with normal ovarian response. Design Retrospective, matched, multicenter cohort study. Setting Private IVF centers. Patient(s) This study analyzed 564 completed IVF cycles in which an average of 12–18 oocytes were retrieved. In 435 cycles the conventional strategy was applied, with initial ET followed by frozen embryo replacements, whereas in 129 cycles the freeze-all policy was performed, with elective cryopreservation and deferred use of all viable embryos. Intervention(s) None. Main Outcome Measure(s) The primary endpoint was CLBR. The secondary endpoint was cumulative clinical pregnancy rate. Result(s) Overall, statistically comparable CLBRs were achieved in the fresh/frozen and freeze-all groups (45.5% vs. 53.5%). Stratification of data for age and number of retrieved oocytes confirmed the absence of differences between the two groups. In a subanalysis in which the day of ET and cryopreservation were taken into account, a similar outcome was achieved in cleavage-stage groups (45.6% vs. 46.4%), whereas when ET was performed at the blastocyst stage the CLBR was significantly higher in the freeze-all group (45.3% vs. 66.7%). Conclusion(s) Our CLBR analysis indicates that clinical performance of the freeze-all policy is equivalent to that of the conventional strategy when ET is carried out at the cleavage stage. However, it seems to be superior if associated with cryopreservation and transfer at the blastocyst stage.
- Published
- 2018