Consistent and predictable delivery rates after oocyte vitrification: an observational longitudinal cohort multicentric study

Purpose While stimulation of women prior to assisted reproduction is associated with increased success rates, the total biological pregnancy potential per stimulation cycle is rarely assessed. Methods Retrospective sequential cohort study of the cumulative live birth rate in 1148 first IVF/ICSI-cycles and 5-year follow up of frozen embryo replacement (FER) cycles were used. Oocyte number, number of embryos transferred, and cryopreserved/ thawed and transferred embryos in a FER cycle were registered for all patients. Children per oocyte and per transferred embryo and percentage of cycles with births were calculated. Results We obtained 9529 oocytes. Embryos (2507) were transferred in either fresh or FER cycles, resulting in 422 births and 474 live born children. Median age of the women was 32.5 years (range 20-41.5 years). In total, 34.3 % of all cycles ended with a live birth while in 65.7 % of the cycles, no oocytes were capable of developing into a child. The average number of oocytes needed per live born child after transfer of fresh and thawed embryos was 20 as only 5.0 % of oocytes aspirated in the first IVF/ICSI cycle had the competence to develop into a child. Conclusions In our setting, overall 5.0 % of the oocytes in a first cycle were biologically competent and in around 2/3 of all cycles, none of the oocytes had the potential to result in the birth of a child.

Section: Discussionsupporting

confidence: 91%

The total pregnancy potential per oocyte aspiration after assisted reproduction—in how many cycles are biologically competent oocytes available?

Lemmen

Rodríguez

Andreasen

et al. 2016

“…Overall, results obtained in the present investigation confirmed previous studies demonstrating the safety and the efficiency of opened system based vitrification techniques (oocytes are directly in contact with liquid nitrogen during vitrification) [1][2][3][4][5][6][7][8]13]. Since closed system based vitrification techniques are mostly used in France, it is worth testing these Fig.…”

Section: Discussionsupporting

confidence: 89%

“…This difference in clinical outcome seems to illustrate a selection bias. Nevertheless, internal evaluation [13], along with other published data, demonstrate that oocyte vitrification does not impact subsequent biological and clinical outcomes in the context of infertility management [7,8,24].…”

Section: Discussionmentioning

confidence: 99%

“…Oocyte vitrification is widely used in assisted reproductive technology (ART) laboratories for several indications like diminution of frozen embryo number and egg banking for donation to fertility preservation [1][2][3][4][5][6][7][8]. To date vitrification is the most attractive and reliable option to store oocytes, bringing about a dramatic change in the field of ART [9,10].…”

Section: Introductionmentioning

confidence: 99%

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Morphokinetics analysis of embryos derived from vitrified/warmed oocytes

Montjean

Geoffroy-Siraudin

Boyer

et al. 2015

Purpose Oocyte vitrification is a worldwide used technique that has proved its worth. Although it was shown not to alter oocyte integrity, a recent study concluded that it may affect oocyte embryo development. As the morphology and kinetics of embryos derived from sibling fresh and vitrified oocytes have not been described previously, the present study evaluates cleavage rate, blastomeres size, fragmentation rate, and blastocyst formation in vitrified/warmed oocyte derived embryos (VODE) as compared with sibling fresh oocytes derived embryos (FODE). Methods This investigation included 90 infertility cases displaying large cohort of mature oocytes at pick up, divided into 2 groups after denudation. A part of oocytes underwent ICSI while others were vitrified. Oocyte warming cycles were performed when no pregnancy was achieved using fresh eggs. Zygote to blastocyst development was recorded prospectively in an image database up to day 5. Results VODE did not show major difference as compared with FODE in terms of cleavage rate, number of blastomeres, fragmentation rate, and blastomeres size. Furthermore, percentage of morulae at day 4 and blastocysts at day 5 are not affected by oocyte vitrification. Conclusion Although our results show that embryo development is not altered by oocyte vitrification, offspring follow-up is essential to exclude any adverse developmental effect of the technique.

“…However, there are some limitations to performing oocyte or embryo cryopreservation in cancer patients. Studies by Rienzi et al and Cobo et al show that around 20 oocytes are required to achieve a live birth [23,24]. This number can be obtained in egg donation programs or in case of fertility preservation for social reasons, but rarely in women with cancer.…”

Section: Discussionmentioning

confidence: 99%

Utilization rates and results of long-term embryo cryopreservation before gonadotoxic treatment

Dolmans

Ouderaen

Demylle

et al. 2015

Purpose The aim of this study was to evaluate long-term embryo cryopreservation, utilization, and success rate in patients subjected to gonadotoxic treatments in the context of cancer. Methods This is a retrospective study on patients (n=54) undergoing ovarian stimulation and IVF for fertility preservation between January 1997 and June 2014. Embryos were slowfrozen and stored until the women were cured and able to undergo embryo transfer. Results Fifty-four women underwent 66 oocyte pick-up procedures in total, and embryos were obtained from 52 of the 54 patients. Four patients died before their frozen embryos could be thawed. Of the remaining 48, 9 women returned to use their embryos, resulting in 6 pregnancies (66 % cumulative pregnancy rate), two of which ended in miscarriage. The live birth rate per patient was thus 44 % (4/9). The true come-back rate, calculated after applicable exclusions, was found to be 23 %. Conclusion IVF followed by embryo freezing is a widely established technique for fertility preservation, but little has been published on the outcomes in cancer patients. While we found the number of good-quality embryos to be lower than in a normal population, the cumulative live birth rate was similar to that achieved with fresh embryos in non-cancer patients. The utilization rate of this fertility preservation method can be considered high.