Egg-Nuclear/Genetic Disorder
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Hi Dr. Smith
On what day of development/culture for the embryo, can you tell if there is an nuclear or genetic disorder with the egg?
If there is slow division or excessive fragmentation, are you saying that is cytomoplasm of the egg and can that occur bc due to the poor drug stimulation of the egg in the follicle?
Do all IVF labs requrie an on sight Lab director that is board certified?
When you accept embryos into your lab, from other facilities, what things do you verify about the embryos from the other lab?
thanks for your help
Brenda
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A1. Up until the 4-cell stage development, the embryo is on autopilot. Once activated, the fertilized egg will divide twice (in most instances) to the 4-cell stage. However, if it is to continue development, it requires further genetic instructions. Between the 4-cell and 8-cell stage of development, the genetic blueprint of the developing embryo becomes the driving force. This is called activation of the embryonic genome. At the same time as genome activation, the embryo does a cross check (specific mechanism unknown) that allows it to detect an abnormal number of chromosomes in the cells of the embryo. If there is a problem (aneuploidy, incorrect chromosome number), the embryo will (in >90% of cases) stop growing. Provided the culture conditions were adequate for embryo development, this is the main reason embryos stop growing prior to implantation. I should point out that this cross check is not 100% effective and some aneuploidies will continue development (tripolidy of chromosome 21 is an example).
A2. Although excessive fragmentation and slow division are associated with genetic abnormalities, it is not necessarily a cause and effect. In most cases, excessive fragmentation and/or slow division prior to the activation of the embryonic genome (during the autopilot phase) are a result of problems with the egg cytoplasm. Inadequate cytoplasmic maturation during ovarian stimulation is the most common cause.
A3. No. According to the Society for Assisted Reproduction (SART, a voluntary compliance organization), a board certified laboratory director can direct up to 3 IVF labs (one onsite, two offsite). According the Center for Medicare and Medicaide (CLIA, a federal law), a Director can direct up to 5 clinical labs.
A4. If the embryos are from within the U.S., we verify that infectious disease testing was done within 30 days prior to the IVF procedure and the patients were negative for all infectious diseases. We verify the stage and grade of the embryos by reviewing the laboratory records. And finally, we verify the freezing and thawing protocol so that we may thaw them the way we are supposed to be thawed (there are a few different protocols out there). We do not accept embryos generated outside the U.S. for a bunch of complicated reasons and the federal restrictions on the transport of potentially biohazardous materials into the country.
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