Birth of two babies using oocytes that were cryopreserved in a choline-based freezing medium

Quintans, C.J.; Donaldson, M.J.; Bertolino, M; Pasqualini, R.S.

doi:10.1093/humrep/17.12.3149

Cited by 138 publications

(56 citation statements)

References 15 publications

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“…With the advent of improved protocols [4,34,35], novel ultrastructural evidence was generated. Comparing fresh oocytes with others frozen with a CRSC involving 0.1 mol/l sucrose as an extracellular CPA, Ghetler et al [36] found massive reduction in the number of CG as a effect of cryopreservation, concluding that stored oocytes should be microinjected rather than inseminated by standard IVF to prevent possible fertilization failure secondary to zona hardening.…”

Section: Discussionmentioning

confidence: 99%

Qualitative and morphometric analysis of the ultrastructure of human oocytes cryopreserved by two alternative slow cooling protocols

Coticchio¹,

Borini²,

Distratis³

et al. 2010

J Assist Reprod Genet

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Purpose To ascertain possible cell damage from cryopreservation, the ultrastructure of human oocytes cryopreserved by slow cooling was assessed. Materials and methods Cryopreservation was performed through two protocols with one-step or two-step propanediol. Fresh control oocytes were examined for comparison. Samples were processed for transmission electron microscopy analysis. Results By light microscopy, both fresh and frozen-thawed oocytes appeared regularly rounded, with intact zona pellucida, and homogeneous cytoplasm. By electron microscopy observation, organelles were abundant and uniformly dispersed. Mitochondria-smooth endoplasmic reticulum associations appeared regular. However, both the amount and density of cortical granules appeared abnormally reduced in frozen-thawed samples. Slight to moderate vacuolization was also found in the ooplasm of oocytes of both frozen groups. Conclusions Slow cooling ensures a good overall preservation of human oocytes. However, cytoplasmic vacuolization and cortical granule loss appears associated with cryopreservation, irrespective of the protocol used.

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Section: Discussionmentioning

confidence: 99%

Qualitative and morphometric analysis of the ultrastructure of human oocytes cryopreserved by two alternative slow cooling protocols

Coticchio¹,

Borini²,

Distratis³

et al. 2010

J Assist Reprod Genet

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“…Although this is a significant improvement, it should be noted that vitrification of mouse MII oocytes already yields even greater survival rates of ∼95% (Dela Pena et al, 2001;Lane and Gardner, 2001). Furthermore, the impact of choline-based slow freezing on human oocyte cryopreservation is unclear because there is yet to be a published, scientific comparison with a sodium-depleted medium (Quintans et al, 2002;Boldt et al, 2003).…”

Section: Discussionmentioning

confidence: 99%

1,2-propanediol and the type of cryopreservation procedure adversely affect mouse oocyte physiology

Larman¹,

Katz-Jaffe²,

Sheehan³

et al. 2006

Human Reproduction

113

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BACKGROUND: The aim of this work was to examine the effect of 1,2-propanediol (PrOH) and type of cryopreservation procedure (slow freezing and vitrification) on oocyte physiology. METHODS: Intracellular calcium of mouse metaphase II (MII) oocytes was quantified by fluorescence microscopy. The effect of PrOH on cell physiology was further assessed through analysis of zona pellucida hardening and cellular integrity. Protein profiles of cryopreserved oocytes were generated by time-of-flight mass spectrometry (TOF-MS). RESULTS: PrOH caused a protracted increase in calcium, which was sufficient to induce zona pellucida hardening and cellular degeneration. Using 'nominally calcium free' media during PrOH exposure significantly reduced the detrimental effects. Proteomic analysis identified numerous up-and down-regulated proteins after slow freezing when compared with control and vitrified oocytes. CONCLUSIONS: Using such approaches to assess effects on cellular physiology is fundamental to improving assisted reproduction techniques (ART). This study demonstrates that PrOH causes a significant rise in intracellular calcium. Using calcium-free media significantly reduced the increase in calcium and the associated detrimental physiological effects, suggesting that calcium-free media should be used with PrOH. In addition, analysis of the oocyte proteome following cryopreservation revealed that slow freezing has a significant effect on protein expression. In contrast, vitrification had a minimal impact, indicating that it has a fundamental advantage for the cryopreservation of oocytes.

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“…Following successful reports in the mid-1990s (11)(12)(13)(14), an equilibrium freezing method using propylene glycol (PG) as the penetrating cryoprotective agent (CPA) has become the most utilized method to freeze human oocytes (15). Fabbri and colleagues (16) demonstrated a significant improvement in survival when the concentration of sucrose in the freezing medium was increased to 0.3 mol/L; reports of live births using this method or slight variations followed (17)(18)(19)(20)(21). Despite these promising results, very recent reports, some using large cohorts of patients, suggest that the current methods are still sub-optimal (22)(23)(24).…”

Section: Introductionmentioning

confidence: 99%

Human oocyte vitrification: the permeability of metaphase II oocytes to water and ethylene glycol and the appliance toward vitrification

Mullen

Mei

et al. 2008

Fertility and Sterility

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Objectives-To determine the permeability of human metaphase II oocytes to ethylene glycol and water in the presence of ethylene glycol, and to use this information to develop a method to vitrify human oocytes.Design-An incomplete randomized block design was used for this study.Setting-A University-affiliated assisted reproductive center.Patients-Women undergoing assisted reproduction in the Center for Reproductive Medicine at Shandong University.Interventions-Oocytes were exposed to 1.0 molar ethylene glycol in a single step, and photographed during subsequent volume excursions.Main outcome measures-A 2-parameter model was employed to estimate the permeability to water and EG.Results-Water permeability ranged from 0.15 to 1.17 µm/(min·atm), and ethylene glycol permeability ranged from 1.5 to 30 µm/min between 7 °C at 36 °C. The activation energies for water and ethylene glycol permeability were 14.42 Kcal/mol and 21.20 Kcal/mol, respectively. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.Some of the results from this study were presented at the 62 nd annual meeting of the American Society for Reproductive Medicine, 21-25 October 2006, in New Orleans, LA USA. Conflict of Interest: None. CapsuleHuman metaphase II oocyte permeability to ethylene glycol was determined. A method for vitrification, based upon fundamental principles, was developed from these data. Conclusions-Despite the lower permeability of human MII oocytes to ethylene glycol compared to previously published values for propylene glycol and dimethylsulfoxide, methods to add and remove human oocytes with a vitrifiable concentration of ethylene glycol can be designed which prevent excessive osmotic stress and minimize exposure to high concentrations of this compound. NIH Public Access

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Birth of two babies using oocytes that were cryopreserved in a choline-based freezing medium

Abstract: To the best of our knowledge, these are the first pregnancies and normal births using oocytes that were cryopreserved in a choline-based medium. The small sample size prevents us from concluding that freezing in a low-sodium medium is superior to using a conventional one.

Cited by 138 publications

References 15 publications

Qualitative and morphometric analysis of the ultrastructure of human oocytes cryopreserved by two alternative slow cooling protocols

Qualitative and morphometric analysis of the ultrastructure of human oocytes cryopreserved by two alternative slow cooling protocols

1,2-propanediol and the type of cryopreservation procedure adversely affect mouse oocyte physiology

Human oocyte vitrification: the permeability of metaphase II oocytes to water and ethylene glycol and the appliance toward vitrification

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