For Patients

When is PGD/PGS performed?

PGD/PGS is performed by sampling the developing egg/embryo at different time points. We can customize your testing strategy to obtain the most accurate diagnosis for your embryos. Your indication as well as your IVF physician will determine which biopsy type is best for you.

  • Blastocyst/trophectoderm biopsy

    A blastocyst is an embryo that has developed to the Day 5/6 stage. Blastocyst biopsy involves the removal of a small number of cells from the outer layer, known as the trophectoderm. Blastocyst testing typically requires that embryos are cryopreserved (frozen) after biopsy, and healthy embryos are later thawed and transferred during a future cycle. This biopsy method is recommended for a majority of cases, and offers optimal accuracy.

  • Blastomere biopsy

    A blastomere is an embryo that has developed to the Day 3 (cleavage) stage. Blastomere biopsy involves the removal of one cell from the developing embryos. Results of blastomere testing are typically available in time for a Day 5 transfer in the same IVF cycle.

  • Polar body biopsy

    Polar bodies are the by-products of egg division. These cells do not serve any role for the egg or embryo and will naturally degrade; however, they can be removed and tested to determine the genetic status of the egg. Polar body testing only tests for the maternal genetic contribution to the embryo and occurs at the Day 0 and/or Day 1 stage. Both polar bodies must be removed and tested in order to make an accurate diagnosis, and therefore, fertilization of the egg is necessary. For couples in which discarding fertilized embryos is not an option, cryopreservation (freezing) can occur prior to the fusion of the egg and sperm nuclei (2PN stage). Results of polar body testing are typically available in time for a Day 3 or Day 5 transfer in the same IVF cycle.