【Abstract】 Objective To describe the clinical application of fluorescence in situ hybridization (FISH) in preimplantation gender diagnosis.Methods Preimplantation gender diagnosis was performed in 2 female hemophilia A carriers, 1 male patient with glucose-6-phosphate dehydrogenase (G-6-PD) deficiency and 2 male patients with Y chromosome abnormality. Embryo sex was identified by FISH in total of 6 treatment cycles.Results A total of 123 cumulus-oocytes were retrieved in 6 treatment cycles. Sixty-one embryos were available for embryo biopsy. The success rate of biopsy was 86.9% (53/61), with a further cleavage rate of 62.3% (33/53). In the FISH procedure, one cell was lost during fixation, leading to a 98.1% (52/53) fixation rate. Totally, 16 female embryos and 3 male embryos were transferred to 5 patients in 6 cycles. Three healthy babies were born. The diagnosis was confirmed by subsequent analysis of amniocytes and embryonic buds after embryo reduction.Conclusions FISH is an efficient and reliable technique for determining the sex of human preimplantation embryos. Selective abortion and births of affected children can be avoided by preimplantation gender diagnosis.更多还原