Egg Freezing

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Oocyte Egg Cryo Preservation

Oocyte Egg Cryo Preservation

Egg freezing (oocyte cryopreservation) is a relatively new technology in which a woman's eggs are retrieved, frozen and stored for future use. Later, when she is ready to become pregnant, the eggs can be thawed, fertilized, and embryos created will be transferred to the uterus to result in a pregnancy.

Egg freezing is particularly important for following three groups of women:

  1. Women who are diagnosed with cancer and prior to chemotherapy or radiation therapy (as both are toxic to oocytes) and they desire to preserve their fertility;
  2. Women undergoing IVF treatment who do not consider embryo freezing an option due to religious or ethical reasons;
  3. Women who would like to preserve their fertility, either because they do not yet have a partner, or for other personal or medical reasons, or partner is not available at the time of egg retrieval.

The egg retrieval process for oocyte cryopreservation is the same as that for in-vitro fertilization. For patients who choose Natural Cycle IVF, no medication is needed but only one egg will be retrieved per menstrual cycle. This option may be suitable for patients who do not wish to use any fertility drug, or patients who has diminished ovarian reserve and not suitable for ovarian stimulation; For patients who choose Minimal Stimulation IVF, 4-6 eggs will usually be retrieved each cycle; this option is suitable for many patients who desire to preserve fertility but do not wish to use too much fertility medication. For patients who choose Conventional IVF, 10-20 eggs may be retrieved. This option may be suitable for younger patients and who only wish to do one time IVF. The detailed treatment protocol and egg retrieval procedure you may see various IVF option sections. After egg retrieval, the eggs will be evaluated by embryologist to determine if the eggs are mature (MII stage), only those mature eggs will be cryo-preserved. The immature eggs may be cultured for additional 24 hours, if they become mature and they will be cryo-preserved as well. If the eggs are still not mature after additional 24 hours couture, these eggs will then be discarded. Recent studies have shown that the rate of birth defects and chromosomal abnormalities when using cryo-preserved oocytes is the same as that of natural conception.

There are two methods for oocyte cryopreservation

Oocyte Egg Cryo Preservation

1. Slow freezing; and 2. Vitrification. The vitrification is a new flash-freezing process which is associated with much higher survival rates and better development for oocyte. At LIFE, only vitrification is used for our oocyte cryopreservation. Our freezing and thaw survive rate is > 95%. We recommend the optimal age to preserve oocyte is between 30 to 40 years old. However, oocyte cryopreservation can be done at any reproductive age. At LIFE, our youngest patient who did egg cryopreservation was 21, and our oldest patient was 49.