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Updated: Nov 6, 2025
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Collection and Cryopreservation of Hamster Oocytes and Mouse Embryos
Published on: March 27, 2009
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PERSPECTIVE: Cryopreservation of Human Oocytes and the 'Carryover' Effect on Early Embryo Development
1Institute of Biothermal Science and Technology, School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China.
Cryo Letters
|May 10, 2021
Summary
Oocyte cryopreservation, especially slow freezing, can negatively impact early human embryo development. Vitrification offers better survival and fertilization rates, but a
Area of Science:
- Reproductive Medicine
- Developmental Biology
- Cryobiology
Background:
- Delayed childbearing and declining fertility are global concerns.
- Oocyte cryopreservation offers fertility preservation for women facing medical or personal reasons for delayed conception.
- Understanding the impact of oocyte cryopreservation on subsequent embryo development is crucial.
Purpose of the Study:
- To review and analyze the effect of oocyte cryopreservation on early human embryo development.
- To compare the outcomes of different cryopreservation techniques (slow freezing vs. vitrification).
Main Methods:
- Systematic review and meta-analysis of clinical studies published between 1999 and 2020.
- Searched databases: Medline, PubMed, and Web of Science.
- Analyzed data on oocyte survival, fertilization, and early embryo development.
Main Results:
- Vitrification significantly improves oocyte survival (84.7%) compared to slow freezing (58.0%).
- Vitrification leads to higher rates of fertilization, cleavage, and embryo implantation compared to slow freezing.
- A negative 'carryover' effect on embryo development (cleavage, implantation) is observed, greater with slow freezing than vitrification.
Conclusions:
- Oocyte cryopreservation can negatively impact early human embryo development, though vitrification mitigates this effect compared to slow freezing.
- The 'carryover' effect suggests subtle alterations affecting later development, potentially involving hypothermia, ion channels, metabolism, or epigenetics.
- Future research should investigate epigenetic changes beyond oocyte survival and fertilization rates.
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