RETRACTED ARTICLE: Can fresh embryo transfers be replaced by cryopreserved-thawed embryo transfers in assisted reproductive cycles? A randomized controlled trial

Purpose The aim of this study is to compare implantation and live birth rates (LBR) between fresh euploid embryo transfers versus cryo-all cycles with a subsequent embryo transfer into a prepared endometrium. Material and Methods This is a retrospective cohort study. Patients who underwent an IVF cycle with PGS with trophectoderm biopsy from January 2011 to July 2015 were included. Patients were divided into three groups: "Fresh Only," "Frozen Embryo Transfer ('FET) Only," and "Fresh ET then FET." For "Fresh Only" group (n = 345), PGS results were received within 24 h. For "FET Only" group (n = 514), results were expected after 24 h, and embryos were cryopreserved after biopsy; only FET was performed in this group (no fresh transfer). For "FET with a previous fresh ET" (n = 139) group, patients underwent a fresh ET with a subsequent FET, in which the same cohort of embryos was utilized. The main outcome measures were pregnancy rate (PR), clinical PR, implantation rate (IR), LBR, and early pregnancy loss rate. Results IRs were statistically higher in the "FET Only" group when compared to the "Fresh Only" group (59.5 vs. 50.6 %, p < 0.01) and the "FET with a previous fresh ET" (59.5 vs. 50.6 %, p < 0.05). LBR was statistically significant in the "FET Only" group when compared to the "Fresh Only" group (57.6 vs. 46.5 %, p < 0.005) but not when compared to "FET with a previous fresh ET" group (57.6 vs. 47.7 %, p = 0.07). Conclusions This analysis suggests euploid embryos to be more likely to implant and achieve a LBR in a synthetic FET cycle than in a fresh cycle.

Section: Discussionmentioning

confidence: 99%

Reproductive outcome is optimized by genomic embryo screening, vitrification, and subsequent transfer into a prepared synchronous endometrium

Rodriguez-Purata

Lee

Whitehouse

et al. 2016

“…Dizygotic twinning was also eliminated in the repeat SET model, whereas the repeat DET model predicted a 20.9 % twin rate with a lower overall live birth rate (39.0 % vs. 41.4 %; [26]). Moreover, there is accumulating evidence that both pregnancy rates [1,27,[30][31][32] and obstetric and neonatal outcomes [11,19] may be improved in cryopreserved cycles, specifically due to uncoupling the processes of COH and embryo transfer. Thus, as routine cryopreservation may emerge as a method to optimize the safety and efficacy of assisted reproduction, the development of prediction models specific to eSET in cryopreserved cycles will become increasingly important, as recently published for fresh embryo transfers [14,36].…”

Section: Discussionmentioning

confidence: 99%

Predictors of twin live birth following cryopreserved double embryo transfer on day 3

Kaser

Missmer

Correia

et al. 2013

Purpose To determine embryo and cycle-specific parameters associated with twin live birth in day 3 cryopreserved double embryo transfer (DET) cycles, and to propose a new prediction model for external validation. Methods All cycles with autologous or donor cryopreserved DET of day 3 embryos from 2002 to 2011 at a single academic institution with a singleton or twin live birth were included (n=207). Patient characteristics, post-thaw embryo morphology and freeze-thaw parameters were compared between patients with a single and twin live birth. Results Demographic characteristics were similar, except that patients delivering twins were younger at age of cryopreserved embryo transfer (CET), fewer were parous and more were anovulatory. Duration of embryo storage, time in culture post-thaw, endometrial thickness and use of assisted hatching were comparable. Six predictors of twin delivery were identified: patient age <35 year at CET, intact survival of the lead embryo, resumption of mitosis, 7-8 viable cells in the non-lead embryo, transfer of a lead embryo with ≥7 cells and a sum of ≥14 viable cells in the two transferred embryos. Regression modeling predicted a step-wise increase in the probability of twins with addition of each predictor; with all six present, the risk of twins was predicted to be 53 % and with none present, the risk decreased to 6 %. Conclusions The six identified variables associated with twin live birth following day 3 cryopreserved DET have been applied to derive a prediction model for estimating the risk of twin delivery. External validation of the model is required prior to clinical application.

“…However, it is still uncertain whether this strategy might be beneficial for all patients that are submitted to ART treatments [6,16]. A recent meta-analysis showed an increase in ongoing pregnancy rates (OPR) when the freeze-all strategy was performed when compared to fresh embryo transfer [14]; however, there were only three studies included in this meta-analysis [13,17,18]. Furthermore, one of the included studies [17] was retracted due to methodological flaws.…”

Section: Introductionmentioning

confidence: 99%

“…A recent meta-analysis showed an increase in ongoing pregnancy rates (OPR) when the freeze-all strategy was performed when compared to fresh embryo transfer [14]; however, there were only three studies included in this meta-analysis [13,17,18]. Furthermore, one of the included studies [17] was retracted due to methodological flaws. A recent published study evaluated the freeze-all policy in IVF cycles with preimplantation screening (PGS) and also demonstrated benefit in performing elective cryopreservation of all embryos [19].…”

Section: Introductionmentioning

confidence: 99%

Freeze-all cycle for all normal responders?

Roque

Valle

Guimarães

et al. 2016

Purpose The purpose of this study is to evaluate the freeze-all strategy in subgroups of normal responders, to assess whether this strategy is beneficial regardless of ovarian response, and to evaluate the possibility of implementing an individualized embryo transfer (iET) based on ovarian response. Methods This was an observational, cohort study performed in a private IVF center. A total of 938 IVF cycles were included in this study. The patients were submitted to controlled ovarian stimulation (COS) with a gonadotropin-releasing hormone (GnRH) antagonist protocol and a cleavage-stage day 3 embryo transfer. We performed a comparison of outcomes between the fresh embryo transfer (n = 523) and the freezeall cycles (n = 415). The analysis was performed in two subgroups of patients based on the number of retrieved oocytes: Group 1 (4-9 oocytes) and Group 2 (10-15 oocytes). Result(s) In Group 1 (4-9 retrieved oocytes), the implantation rates (IR) were 17.9 and 20.5% (P = 0.259) in the fresh and freeze-all group, respectively; the ongoing pregnancy rates (OPR) were 31 and 33% (P = 0.577) in the fresh and freezeall group, respectively. In Group 2 (10-15 oocytes), the IR were 22.1 and 30.1% (P = 0.028) and the OPR were 34 and 47% (P = 0.021) in the fresh and freeze-all groups, respectively. Conclusion(s) Although the freeze-all policy may be related to better in vitro fertilization (IVF) outcomes in normal responders, these potential advantages decrease with worsening ovarian response. Patients with poorer ovarian response do not benefit from the freeze-all strategy.