POTENTIAL USE OF REPEATED FLUORESCENCE IN-SITU HYBRIDIZATION IN THE SAME HUMAN BLASTOMERES FOR PREIMPLANTATION GENETIC DIAGNOSIS

Objective: To assess the feasibility of repeated fluorescence in situ hybridization (FISH) procedures in the same nucleus of a human blastom ere. Design: Three consecutive FISH procedures were performed in the s ame human blastomere by using direct label fluorescence CEP and WCP pr obes (Vysis). Setting: Hospital-based private IVF program. Patient(s): Twenty-eight infertile couples who underwent conventional IVF in our center. Intervention(s): Embryos from oocytes with three pronuclei aft er in vitro insemination were used in this study. Main Outcome Measure (s): The rates of nuclear loss, present signals, and absent signal wer e examined. Result(s): In group 1, the rates of presence of signals we re 94% after the first FISH, 92% after the second FISH, and 85% after the third FISH. In group 2, the rates of presence of signals were 96% after the first FISH, 93% after the second FISH, and 87% after the thi rd FISH. There was no statistically significant difference in the rate s of nuclear loss, present signals, and absent signal between three co nsecutive FISH procedures and between CEP and WCP probes. Conclusion(s ): Six or more chromosomes of a single blastomere may be examined with use of this repeated FISH procedure, which may be important for preim plantation genetic diagnosis. (Fertil Steril(R) 1998;70:729-33. (C) 19 98 by American Society for Reproductive Medicine.).