Genetics - Preimplantation diagnostics

On this page you will find information about:

• Infertility and genetics
• Types of Preimplantation Genetic Diagnosis (PID)
• Legal requirements
• Latest scientific findings

You have been trying to get pregnant for a long time and have opted for artificial insemination (IVF, ICSI). Your desired child should get the best possible start in life and be born without serious health problems, but there is a hereditary genetic or chromosomal disease in your family, or either yourself or your partner is affected.

Through pre-implantation diagnosis we clarify whether your eggs or embryos are healthy. It allows us to select specific unencumbered oocytes or embryos and to avoid genetic defects in your baby.

infertility and genetics

The health of a child depends largely on the health of their genes. These genes, their genetic material, are located in the chromosomes. A human basically has 23 + 1 chromosome pairs, where the individual genes are stored. For almost all genetically determined human characteristics, the individual genes must be present on both parts of their chromosome pair.

In some people, individual genes are "shifted" (translocation). They are located only on one chromosome of the chromosome pair. As a result, some genes are duplicated on one chromosome, others are not. Simple translocations can be detected by a blood sample (karyogram).

Polar body diagnostics (PBD)

Shortly after the sperm has penetrated into the egg shell, the egg cell forms two polar bodies. These are no longer needed later and die. They contain DNA copies of the nucleus.

For the examination, we take both polar bodies before the embryo develops. By diagnosing these genetic copies, not the nucleus, we clarify whether the woman has genetic disorders, genetic defects or structural chromosome disorders.

It is not possible to determine sex or to analyze male genetic material.

At the time of removal of the polar bodies, egg and sperm cells have not yet fused together. There has not been any fertilization. Therefore, the eggs are artificially fertilized by injection of each sperm (ICSI) and further developed during the period of the polar body examination. The examination takes about three days. Then we select those embryos for the transfer, which originated from the genetically suitable oocytes. Since the examination takes place before fertilization, the polar body diagnosis is ethically less controversial than the other methods of preimplantation genetic diagnosis. The method is error-prone, because "only" the copy of the female genome is examined. It also allows no statement about the male genome.

Trophectoderm biopsy (TOBI)

The trophectoderm biopsy takes place after the fertilization. The embryo develops on day 5 or 6 after fertilization to a so-called blastocyst, a germinal vesicle. For the examination, we take a few cells from this blastocyst. The embryo core, from which the child develops, remains untouched. The taken trophectoderm cells play no role for the further development of the embryo. For the genetic examination, we freeze the cells taken. Their examination allows to detect changes in the genome and to exclude affected embryos from transfer to the uterus.

Latest scientific findings

In genetic diagnostics, the experts assume that all cells of a blastocyst carry the same set of chromosomes.

In recent years there are increasing suspicions that the so-called euploid cells - cells with a complete set of chromosomes - are located more in the embryo nucleus, which is the part of the embryo from which the child develops. Non-euploid (aneuploid) cells are likely to occur more in the trophoblast, which are the cells that are examined by trophectoderm biopsy. If the cells taken by biopsy are euploid, it can be concluded that this also applies to the embryo. If aneuploid cells are detected, the situation remains a bit unclear. It may or may not be the case that the embryo is affected as well.

There is a hereditary disease in your family? You had several unsuccessful attempts of IVF treatment?
Arrange an initial meeting with us. We will inform you in detail about the methods of preimplantation genetic diagnosis and the possibilities of artificial insemination.