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Escrich L.,Universitary Institute Valencia | Grau N.,Universitary Institute Valencia | Mercader A.,Universitary Institute Valencia | Rubio C.,Universitary Institute Valencia | And 3 more authors.
Journal of Assisted Reproduction and Genetics | Year: 2011

Purpose: To define germinal vesicles (GV) by morphometric and morphologic examination and by chromatin compaction and to assess their spontaneous nuclear and cytoplasmic competence. Materials: 131 GV were cultured for 42.7±2.4 h. Nuclear maturation was evaluated at four time points. Sixty-seven in vitro and twenty-five in vivo metaphase II (MII) were activated. Parthenotes with 2 PB and one pronucleus (NA) were studied for ploidy. Results: A total of 74.8% GV matured to MII: 55% at 21.4±2.4 h and 47.3% in the following 24 h. Artificial activation induced NA in 79.2% of in vivo-MII and in 22.4% of in vitro-MII. All NA were haploid. Conclusions: GV spontaneously mature at the nuclear level. Their NA are haploid, but their cytoplasmic competence is compromised. Variables were not found to be predictors of oocyte competence, probably due to our population being homogeneous with respect to most of the variables studied. © 2010 Springer Science+Business Media, LLC. Source


Escriba M.-J.,Universitary Institute Valencia | Grau N.,Universitary Institute Valencia | Escrich L.,Universitary Institute Valencia | Pellicer A.,Universitary Institute Valencia | Pellicer A.,University of Valencia
Fertility and Sterility | Year: 2010

This article describes a new methodology for preserving and banking isolated human blastomeres, whose originality is based on packing the blastomere into an emptied zona pellucida before vitrification. After warming, 75.7% of blastomeres survived and developed at a rate comparable to that in noncryopreserved blastomeres (62.5% cleavage, 26.6% compaction, and 20.3% cavitation). © 2010 American Society for Reproductive Medicine. Source


Escriba M.-J.,Universitary Institute Valencia | Escriba M.-J.,Universitary Institute | Grau N.,Universitary Institute Valencia | Escrich L.,Universitary Institute Valencia | And 2 more authors.
Journal of Assisted Reproduction and Genetics | Year: 2012

Purpose: To evaluate the recovery rate and spontaneous in vitro maturation (IVM) of immature oocytes enclosed within or released from follicles during the processing of ovarian tissue prior to its cryopreservation. Methods: Thirty-three oncologic patients who had not previously undergone chemo or radiotherapy underwent ovarian tissue cryopreservation (OTC) during natural menstrual cycles. Immature oocytes, enclosed within follicles or released during ovarian cortex processing, were collected and matured spontaneously in vitro for 48 h. Nuclear maturation was assessed every 24 h and the ability of the IVM oocytes to display a normal activation response following parthenogenetic activation was evaluated. The following outcome measures were also evaluated: disease, age, FSH, LH, E2, P4 and AMH serum levels, menstrual cycle day, recovery and spontaneous IVM and parthenogenetic activation rates. Results: Oocytes recovered per patient were 3.3 ± 0.7 (1.8-4.7 oocytes, 95CI), regardless of the menstrual phase. The mean number of IVM oocytes per patient was 1.3 ± 0.2 oocytes (95CI: 0.8-1.8), regardless of menstrual phase (p = 0.86) and oocyte origin (p = 0.61). Forty-one percent of oocytes extruded the second polar body and formed one pronucleus after parthenogenetic activation. Conclusion: Twenty-one of the 33 women (63.6 %) requesting OTC produced at least one mature oocyte. © 2012 Springer Science+Business Media, LLC. Source


Grau N.,Universitary Institute Valencia | Aparicio B.,Universitary Institute Valencia | Escrich L.,Universitary Institute Valencia | Mercader A.,Universitary Institute Valencia | And 5 more authors.
Journal of Assisted Reproduction and Genetics | Year: 2013

Purpose: To determine the survival and subsequent in vitro development of human cleavage stage embryos and hatched blastocysts following varying periods of short-term storage at 4 C, using tripronucleated human embryos (TPN) as a model. Methods: TPN cleavage embryos and hatched blastocysts short-term stored at 4 C for 0 h (control), 24 h and 48 h. The main outcome measures were: survival rates (SR) and in vitro developmental ability (blastocyst rate and blastocyst-re-expansion rate) in each of the groups after storage. Results: Cleavage-stage TPN survived at comparable rates to controls, regardless of storage time (average: 97.3 %). The in vitro development of cleavage-stage TPN stored for 24 h was comparable to that of controls (average 64.7 %), but was significantly impaired when storage lasted 48-h (20.8 %). After artificial shrinkage, SR was comparable in 24-h-stored and non-stored hatched blastocysts (85.7 %; p > 0.05), but was significantly impaired in the 48-h-stored group (20.0 %). Following 24-h storage, the re-expansion rate of hatched blastocysts was similar to that of controls (average: 57.1 %; p > 0.05), but was higher than that of the 48-h-stored group (15.0 %; p < 0.05). Conclusions: TPN human cleavage embryos and blastocysts can be successfully stored short-term for up to 24 h at 4 C without using cryoprotectants without any significant negative impact on survival or subsequent in vitro development. © 2013 Springer Science+Business Media New York. Source

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