Outcome of cryotransfer of embryos developed from vitrified oocytes: double vitrification has no impact on delivery rates.

Evaluate the outcome of cryotransfer of embryos developed from vitrified oocytes. Retrospective cohort study. Private university-affiliated IVF center. Women undergoing warming cycles in which vitrified embryos were developed from vitrified or fresh oocytes. Vitrification by the Cryotop open device. Delivery rate (DR) per warming cycle. A total of 471 warming cycles of 796 vitrified embryos developed from vitrified oocytes (group 1) and 2,629 warming cycles of 4,394 vitrified embryos derived from fresh oocytes (group 2) were evaluated. Overall survival rates were 97.2% [95% confidence interval [CI] 95.9%-98.6%] vs. 95.7% [95% CI 94.9-96.4], respectively. DRs per warming cycle were 33.8% (group 1) and 30.9% (group 2). Double vitrification had no effect on DR (odds ratio [OR] 0.877, 95% CI 0.712-1.080). Confounding factors (ovum donation or autologous cycles; day-3 or blastocyst embryo transfer [ET]; natural or hormonal replacement therapy for ET; single or double ET; previous cycles, number of oocytes, doses of gonadotropins and E2 levels on the day of hCG) did not modify the effect of double vitrification on DR (OR 0.872, 95% CI 0.702-1.084). Vitrification at early cleavage or blastocyst stage of embryos obtained from previously vitrified oocytes has no effect on DR/warming cycle.

Cobo A ，Castellò D ，Vallejo B ，Albert C ，de los Santos JM ，Remohí J ... -  《-》

Outcomes of vitrified early cleavage-stage and blastocyst-stage embryos in a cryopreservation program: evaluation of 3,150 warming cycles.

To assess the outcomes achieved after Cryotop vitrification of both early cleavage and blastocyst-stage embryos and to determine whether the embryo developmental stage and embryo quality as well as the origin of the embryos (ovum donation cycles, patients' own oocytes) and the endometrial preparation for the embryo transfer had any effect on the final outcome. Observational study. Private university-affiliated IVF center. Women undergoing 3,150 warming cycles whose embryos were vitrified due to various reasons. Vitrification by the Cryotop open device. Delivery rate (DR) per warming cycle. Survival rate was 95% (5,722 out of 6,019 embryos). The percentage of intact embryos at warming showing 100% blastomere survival was 93% (95% CI 90.1%-95.3%) for day 2 and 95% (95% CI 94.3%-95.7%) for day 3; 3,057 embryo transfers were performed (3% cancellation rate). The DR/warming cycle was 32.5% (95% CI 30.9%-34.2%). Slight differences in survival rate were found [94.9% (95% CI 93.0%-96.8%) for day 2, 94.2% (95% CI 93.4%-94.9%) for day 3, 95.7% (95% CI 94.5%-96.9%) for day 5, and 97.6% (95% CI 96.9%-98.6%) for day 6]. Overall implantation, clinical pregnancy, ongoing pregnancy, and live birth rates per warming cycle were 35.5% (95% CI 33.5%-38.5%), 41.7% (95% CI 39.9%-43.4%), 32.6% (95% CI 31.0%-34.2%), and 38.1% (95% CI 36.4%-39.8%) respectively. The linear regression model considering embryo developmental stage, ovum donation or patient's own oocytes, and hormonal replacement therapy or natural cycle for endometrial preparation (odds ratio 1.179; 95% CI 0.912-1.277) showed no impact on the DR. Highly successful cryopreservation of all embryo developmental stages is possible with the use of the Cryotop system. There are no variables clearly exerting a negative effect on the survival and delivery rates.

Cobo A ，de los Santos MJ ，Castellò D ，Gámiz P ，Campos P ，Remohí J ... -  《-》

A prospective pilot study comparing fertilization and embryo development between fresh and vitrified sibling oocytes.

Siano L ，Engmann L ，Nulsen J ，Benadiva C ... -  《-》

Obstetric and neonatal outcomes after transfer of vitrified early cleavage embryos.

Liu SY ，Teng B ，Fu J ，Li X ，Zheng Y ，Sun XX ... -  《-》

Successful elective and medically indicated oocyte vitrification and warming for autologous in vitro fertilization, with predicted birth probabilities for fertility preservation according to number of cryopreserved oocytes and age at retrieval.

To evaluate a single treatment center's experience with autologous IVF using vitrified and warmed oocytes, including fertilization, embryonic development, pregnancy, and birth outcomes, and to estimate the likelihood of live birth of at least one, two, or three children according to the number of mature oocytes cryopreserved by elective fertility preservation patients. Retrospective cohort study. Private practice clinic. Women undergoing autologous IVF treatment using vitrified and warmed oocytes. Indications for oocyte vitrification included elective fertility preservation, desire to limit the number of oocytes inseminated and embryos created, and lack of available sperm on the day of oocyte retrieval. Oocyte vitrification, warming, and subsequent IVF treatment. Post-warming survival, fertilization, implantation, clinical pregnancy, and live birth rates. A total of 1,283 vitrified oocytes were warmed for 128 autologous IVF treatment cycles. Postthaw survival, fertilization, implantation, and birth rates were all comparable for the different oocyte cryopreservation indications; fertilization rates were also comparable to fresh autologous intracytoplasmic sperm injection cycles (70% vs. 72%). Implantation rates per embryo transferred (43% vs. 35%) and clinical pregnancy rates per transfer (57% vs. 44%) were significantly higher with vitrified-warmed compared with fresh oocytes. However, there was no statistically significant difference in live birth/ongoing pregnancy (39% vs. 35%). The overall vitrified-warmed oocyte to live born child efficiency was 6.4%. Treatment outcomes using autologous oocyte vitrification and warming are as good as cycles using fresh oocytes. These results are especially reassuring for infertile patients who must cryopreserve oocytes owing to unavailability of sperm or who wish to limit the number of oocytes inseminated. Age-associated estimates of oocyte to live-born child efficiencies are particularly useful in providing more explicit expectations regarding potential births for elective oocyte cryopreservation.

Doyle JO ，Richter KS ，Lim J ，Stillman RJ ，Graham JR ，Tucker MJ ... -  《-》