Efficiency of oocyte cryopreservation: a meta-analysis

Purpose This study aims to determine if in-vitro maturation (IVM) of human immature oocytes should be performed before or after vitrification. Methods A total of 184 immature oocytes were randomly divided into two different groups: 100 were vitrified at metaphase II (MII) stage 24 h-48 h after IVM (group 1) and 84 were immediately vitrified at germinal vesicle (GV) or metaphase I (MI) stages and in vitro matured after warming (group 2). Results Survival rate after warming was similar in both groups (86.9% versus 84.5%). However, oocyte maturation rate per collected oocyte was significantly higher for oocytes matured before vitrification (group 1, 46%) than for oocytes vitrified before IVM (group 2, 23.8%) (p<0.01). Consequently, the number of MII oocytes inseminated per oocyte collected was significantly higher for group 1 (40%) than for group 2 (23.8%) (p<0.05). Conclusion IVM procedure is more efficient when it is performed before oocyte vitrification.

Section: Introductionmentioning

confidence: 99%

In-vitro maturation of human oocytes: before or after vitrification?

Fasano

Demeestere

Englert

2012

“…the actual number of embryos that implant and create pregnancy per number of oocytes frozen) [40]. Viewing success in this way is unique to OC.…”

Section: Oocyte Vs Embryo Cryopreservationmentioning

confidence: 99%

“…Viewing success in this way is unique to OC. Currently available data suggests that the efficiency of fresh IVF, when calculated as live born infant per oocyte is about 5-6% overall [40,41], whereas some studies with frozen oocytes report similar per oocyte efficiencies [15,35]. Efficiency defined in this manner is dependent on a number of variables such as patient age, quality of stimulation, whether there are restrictions on the number of oocytes that can be used, efficiency of embryo transfer, and the like.…”

Section: Oocyte Vs Embryo Cryopreservationmentioning

confidence: 99%

Oocyte cryopreservation: is it time to remove its experimental label?

Noyes

Boldt

Nagy

2010

As more reproductive-age women survive cancer at the expense of gonadotoxic therapy, the need for viable fertility preservation options has become paramount. Embryo cryopreservation, often using donor sperm, has been the standard offered these women over the past 20 years. Preservation of unfertilized oocytes now represents an acceptable and often equally viable alternative, particularly for single women, due to technologic advances made in the past decade. Given such, oocyte cryopreservation's experimental designation and need for IRB approval should thus be revisited.

“…Other studies have focused on number of live births per mature oocyte in the fresh cycles [5] or after oocyte cryopreservation (OC) per thawing cycle [6][7][8]. All these calculations are useful not only to elucidate the overall efficiency/inefficiency of an ART cycle but also because it provides more detailed information Capsule 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: Introductionmentioning

confidence: 99%

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

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.