Preimplantation genetic diagnosis (PGD): The Gothenburg experience

Background A program for preimplantation genetic diagnosis of pre-embryos f rom patients with hereditary disorders was set up in our unit at Sahlgrensk a University Hospital in 1994. The majority of the patients were carriers o f X-chromosome linked disorders; a few patients were translocation carriers . In this paper we describe our experiences of our first 36 cycles, 30 gend er determinations and six analyses of embryos with possible translocations. Methods. Conventional hormone replacement treatment with intracytoplasmic s perm injection to fertilize the eggs followed by blastomere biopsy and fluo rescent in situ hybridization at the eight cell stage was used for sexing a s well as detection of translocations. Results. Out of the 30 cycles in 13 patients: for gender determination, bla stomere biopsies could be carried out in 25 cycles. Transfer of normal fema le embryos (XX) was performed in 18 cycles, resulting in five pregnancies ( pregnancy rate 27.8%) and an implantation rate of 20% per transfer. Three g irls have been born. Hence the take home baby rate was 16.7% per transfer a nd 10% per started cycle. Six cycles (three patients) for detection of tran slocations in embryos were performed. Diagnosis was possible in fc,ur cycle s. Transfer of normal embryos was carried out in one cycle. No pregnancy wa s achieved. Conclusion. Successful PGD in its clinical application demands close collab oration between a large group of specialists. Even so, the success rate is considerably lower than after conventional IVF or ICSI procedures. Taking i nto account the stress caused to the parents facing late interruption of pr egnancy following conventional prenatal diagnosis we are convinced that thi s technique is well worthwhile continuing and refining.