[Impact of sperm DNA fragmentation on the outcome of frozen-thawed blastocyst transfer in in vitro fertilization and embryo transfer].

To study the impact of sperm DNA fragmentation (DF) on the outcome of frozen-thawed blastocyst transfer in in vitro fertilization and embryo transfer (IVF-ET).We retrospectively analyzed 308 cases of routine IVF-ET performed at our Center of Reproductive Medicine from January 2016 to January 2018. According to the sperm DNA fragmentation index (DFI), we divided the patients into a normal DFI (DFI ≤ 15%, n = 114), a moderate DFI (15% < DFI ≤ 30%, n = 103), and a high DFI group (DFI > 30 %, n = 91), and compared the development of embryos and clinical outcomes among the three groups.The blastocyst formation rate was remarkably higher in the normal and moderate DFI groups than in the high DFI group (68.9% and 66.2% vs 58.3%, P < 0.05) but the percentage of available blastocysts exhibited no statistically significant difference between the former two and the latter group (88.1% and 84.0% vs 81.2%, P > 0.05). There were statistically significant differences among the normal, moderate and high DFI groups in the percentage of high-quality blastocysts (80.3% vs 68.8% vs 59.7%, P < 0.05). The implantation rate was dramatically lower in the high DFI group than in the normal and moderate DFI groups (30.4% vs 43.1% and 41.0%, P < 0.05), and so was the clinical pregnancy rate (33.6% vs 43.2% and 40.2%, P < 0.05), but the abortion rate markedly higher in the former than in the latter two groups (16.2% vs 10.0% and 9.8%, P < 0.05).High sperm DFI can not only significantly reduce the rates of blastocyst formation, available blastocysts and high-quality blastocysts, but also decrease the rates of implantation and clinical pregnancy and increase that of abortion after frozen-thawed blastocyst transfer.