The use of PGD, or preimplantation genetic diagnosis, during IVF treatment ensures that healthy embryos, free from genetic disorders can be identified. To test the embryos, the IVF technicians need to extract a few cells from the embryo. A common method of doing this is removing a single cell from the embryo via a biopsy. However, there are various forms of single cell biopsy. While some are quite common in use, some like Polar Body Biopsy aren't the most preferred option.
What Is Polar Body Biopsy?
Polar body is a component of the female egg or ovum. It is not found in the human sperm. The first polar body is already present in the ovum, before fertilization. The second polar body is formed during the early part of fertilization. Polar bodies are needed for cellular division within the embryo. Polar bodies are gradually eliminated as part of cellular development once the embryo is implanted and thus, the developing fetus doesn't contain polar bodies.
What Is Polar Body Biopsy in PGD?
When extracted from the embryo, the polar body carries genetic information from the female. Thus, Polar Body Biopsy is useful for decoding chromosomal disorders related to the female only. While this is useful, it creates the need for further testing since the genetic disorders carried by the father cannot be identified. Some of the chromosomal abnormalities develop during fertilization, and these too are not reflected in the structure of the polar bodies in the embryo. Polar body biopsy's limited application in PGD testing means that it is not the most preferred form of genetic testing in most IVF clinics.