Oocyte vitrification does not increase the risk of embryonic aneuploidy or diminish the implantation potential of blastocysts created after intracytoplasmic sperm injection: a novel, paired randomized controlled trial using DNA fingerprinting.

To assess the impact of oocyte vitrification on aneuploidy and reproductive potential by comparing vitrified and control oocytes from a single patient within a single cycle and a single fresh transfer. Paired randomized controlled trial in which each patient's cohort of mature oocytes was divided into two even groups with half undergoing Cryotop vitrification and rapid warming and half serving as controls. Academic center for reproductive medicine. Forty-four patients with a mean age of 29.9 ± 2.3 years and normal ovarian reserve. Cryotop vitrification of half of mature oocytes. Trophectoderm biopsy with single nucleotide polymorphism microarray analysis for ploidy and DNA fingerprinting. Rate of aneuploidy (primary outcome), fertilization, cleavage, blastulation, and implantation in embryos derived from vitrified and control oocytes. A total of 588 mature oocytes were randomized, with 240/294 (81.6%) surviving vitrification. Among surviving vitrified oocytes, there was a lower fertilization rate with intracytoplasmic sperm injection (77.9% vs. 90.5%; relative risk [RR], 0.86; 95% confidence interval [CI], 0.80-0.93), a lower cleavage rate (90.9% vs. 99.2%; RR, 0.92; 95% CI, 0.87-0.96), and a lower usable blastocyst formation rate per two pronuclei (34.8% vs. 50.8%; RR, 0.68; 95% CI, 0.54-0.86). There was no difference in the rate of embryonic aneuploidy (vitrified, 29.1% vs. control, 26.4%). In paired blastocyst transfers, the ongoing pregnancy rate per embryo transferred was similar (vitrified, 53.9% vs. control, 57.7%). Although the IVF process is less efficient after oocyte vitrification, implantation rates are equivalent and there is no increased risk of aneuploidy. Given the lack of other viable options, this study provides great reassurance to patients and clinicians applying oocyte vitrification for fertility preservation.

Forman EJ ，Li X ，Ferry KM ，Scott K ，Treff NR ，Scott RT Jr ... -  《-》

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

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

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 ... -  《-》

Vitrification of in vitro matured oocytes diminishes embryo development potential before but not after embryo genomic activation.

Sun Y ，Gu R ，Lu X ，Zhao S ，Feng Y ... -  《-》

Vitrification of oocytes produces high pregnancy rates when carried out in fertile women.

To determine the efficiency of our vitrification technique when applied in young fertile women. Clinical research and application. In vitro fertilization center. Twenty-one women were recruited from the navy community with 19 patients finishing the study. Vitrified oocytes with use of the electron microscopic grid method were warmed 6 months after vitrification. Surviving metaphase II oocytes were microinjected for fertilization, and clinical results were evaluated. Survival, fertilization, and cleavage rate. Pregnancy and implantation rate. Three hundred ninety-five oocytes were warmed, of which 320 oocytes (81.0%) survived. Two hundred eighty-five metaphase II oocytes were microinjected for fertilization; 206 of them (72.3%) fertilized, and 53 embryos were transferred to 19 patients (in 20 warming cycles). Twenty-four of 53 transferred embryos (45.3%) implanted as confirmed by ultrasound examination. Of the 20 transfers, 16 resulted in clinical pregnancy (80%), 3 miscarried (15%), and 13 (65%) went on to produce 20 live births, respectively. This is much higher in comparison with our previous data using supernumerary oocytes where the rates of implantation and pregnancy were 6% and 21%. Live-birth rates per warmed oocyte and per injected oocyte were 5.1% and 7.2%, respectively. High pregnancy and implantation rates were observed after 6 months of cryopreservation by vitrification when oocytes from fertile woman were used. Proper screening of candidates for oocyte cryopreservation is of crucial importance to assure a favorable pregnancy outcome.

Kim TJ ，Laufer LR ，Hong SW 《-》