Application Of Two Rounds Of FISH In Preimplantation Genetic Diagnosis

Part Ⅰ Prime study of two rounds of FISHObjective: To search the feasibility of simple and rapid blastomere fixation technique、two rounds of FISH on discarded embryos，analysing incidence of aneuploidy andmosaic at the same time. Methods:24embryos of day3which inappropriate to transfercome from procedure of IVF or ICSI in our reproductive center. The number ofblastomeres are no less than4. After laser drilling on zona pellucida，biopsy the embryounder the system of micromanipulation. Fix blastomeres on glass slide usingHCL/Tween20. After fixation of nuclears，analyse8chromosomes：13，15，16，18，21，22，X and Y using two rounds of FISH and then calculate successful hybridizationrate. At the same time, analyse the incidence of aneuploid and mosaic. Results: Clearsignals can be seen in each round of FISH.72blastomeres from24embryos arebiopsied，fixing69nucleus, the successful rate of fixation is95.8%，the successful rateof hybridization is94.2%.24embryos are screened which include6normal embryos，18abnormal embryos.18abnormal embryos consists of2multiploid embryos、1haploid embryos、8aneuploid embryos、7mosaic embryos.Conclusion: The method oftwo rounds of FISH used in this study is simple、rapid and accurate. Part Ⅱ Clinical application of two rounds of FISHObjective: To search the feasibility of blastomere biopsy、nucleus fixation and tworounds of FISH used in clinical PGD cycles. Methods: All treatment cycles onsisted ofroutine controlled ovarian hyperstimulation(COH), ICSI and observe embryos. Chooseembryos which consists of at least6blastomeres, less than20%fragments ratio tobiopsy. At first，put the embryos into biopsy medium. after laser drilling on zonapellucida，pull the blastomere. Use HCL/Tween20to fix blastomere. The biopsiedembryos are cultivated in blastula medium. Suitable embryos are transferred based onfluorescence in situ hybridization analysis and day5embryo morphlogy. Results: Thetotal number of transferred unaffected embryos is27in16cycles，obtaining4successful pregnancy.1of clinical pregnancy is ectopic pregnancy and the other two isnormal singleton pregnancy. One of them has giving birth to healthy baby who is thefirst offspring of chromosome translocation couple in Anhui province，and the other ispregnanting.Conclusion: This demonstrates that the method is a helpful pathway ofobtain healthy offspring whose parents with higher genetic risk. Our reproductive centerhas ability to carry out PGD.