Clinical aspects on the use of preimplantation genetic diagnosis in couples at risk.

Background: Preimplantation genetic diagnosis (PGD) is a new technique which may become an attractive alternative to traditional prenatal diagnosis for couples at risk of getting children with severe genetic diseases. We here report our experience after the first trials in Sweden.

Methods: On day three after fertilization by intracytoplasmic sperm injection (ICSI) one or two blastomeres were biopsied and diagnosed by fluorescence in situ hybridization (FISH). Gender determination was done in two cases where the female in the couples were carrier of a severe X-chromosome bound disease (Wiskott-Aldrich disease or ornithine transcarbamylase deficiency).

Results: The first couple got an embryo transfer in each of their two treatment cycles. Two female embryos were transferred in the first cycle and one in the second cycle. The second couple did not get any embryo transfer in their two cycles. No clinical pregnancy occurred.

Conclusion: With the rapidly improving knowledge about inherited disease and refinement of the IVF techniques, PGD will play an important clinical role in high risk groups within a decade for both mono- and polygenic disorders. Both technical as well as legal and ethical problems have however to be solved before these new techniques can be applied on large scale.