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Thread: criteria for freezing blasts???

  1. #1
    Join Date
    Feb 2009
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    Default criteria for freezing blasts???

    Dr. Saleh could you help clarify something for me? I would greatly appreciate it. I am very perplexed but i can't find this discussed anywhere. Any help would be greatly appreciacted.

    What is the criteria for freezing day 6 blasts? Why are some discarded? I know grade three blasts have only a 10% chance of making a baby but that is still 10%. Do you freeze day 6 grade 3 blasts? If so, what criteria are used to determine what to freeze and what to discard?

    I don't understand why any are discarded. If they are still alive on day 6 i would think you all would be frozen. If they survived the thaw maybe they are one of those 10% that are good. Am i oversimplifying? Is there a grade below grade 3 and an arrested blast?

    I know grade 3 day 5/6 blasts are transferred in fresh cycles so what is the difference. I am really confused.

    Thank You.

  2. #2
    Join Date
    Oct 2008
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    387

    Default

    My pleasure. Please see below:

    What is the criteria for freezing day 6 blasts? Why are some discarded? I know grade three blasts have only a 10% chance of making a baby but that is still 10%. Do you freeze day 6 grade 3 blasts? If so, what criteria are used to determine what to freeze and what to discard?

    A: That is a subjective decision on the part of the embryologist. The issue is that day 6 embryos are not that great vs. embryos that reached blastocyst stage on day 5. I personally do not like to freeze those as they do not survive the freeze and rarely yeild a healthy pregnancy. That avoids unecessary expenses and anxiety on the part of the patient.

    I don't understand why any are discarded. If they are still alive on day 6 i would think you all would be frozen. If they survived the thaw maybe they are one of those 10% that are good. Am i oversimplifying? Is there a grade below grade 3 and an arrested blast?

    A: That depends on the grading system. We use a grade 1-2-3 system, others use 1 to 5. So a grade 3 for me is the worst category. I definitely freeze grade 2 embryos i.e. average. But not worse grade 3 category. Hope that clarifies.

    I know grade 3 day 5/6 blasts are transferred in fresh cycles so what is the difference
    A: I do not transfer grade 3 as these are mostly chromosomally abnormal. Again using a 3 grade system.

  3. #3
    Join Date
    Feb 2009
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    Default

    Dr. Saleh, thanks for taking the time to answer me. Would you go a little further on this with me if you don't mind? I am actually referring to day 5 blasts that are not frozen until they are re-evaluated on day 6. To my understanding they were blasts on time but the policy is to only freeze blasts after they have been re-evaluated on day 6. In fresh cycles, day 5 blasts usually are the most successful and they are transferred without the added benefit of a re-evaluation on day 6. In fact, there is no way to know what the transferred day five blasts would have looked like on day six for comparison. I have read of success stories for embryos that didn't make it to blast until day 7. So if you are doing a freeze all cycle anyway, why not just freeze them all on day 6 and reevaluate post thaw? I just don't understand why blasts would not be frozen unless they had arrested.

    Thanks again for your time. I know i am asking a lot of questions but i can not this info anywhere. And believe me i have tried.

  4. #4
    Join Date
    Oct 2008
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    387

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    the issue is that poor quality embryos are not that safe to transfer as they have a high chance of miscarriage and possible chromosomal problems.

  5. #5
    Join Date
    Feb 2009
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    11

    Default

    I see. Thank you very much for your time.

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