LAUSR

To investigate the developmental potential and clinical value of embryos with abnormal cleavage rate, a retrospective analysis was performed on 66 635 2-prokaryotic (2PN) and 1-pronuclear (1PN) embryos. The embryos were given conventionally in vitro fertilization (IVF) treatment and continuously cultured on the day 3 (D3) at the Reproductive Medicine Center, Tongji Medical College, Huazhong University of Science and Technology from January 2016 to December 2017. The embryos were separated into the day-2 (D2) undivided group with 106 cases, the arrested development group with 3482 cases, the blastomere reduction group with 541 cases, and the control group with 62 506 cases, respectively. The blastocyst utilization rates of these three abnormal groups were 2.83%, 10.86% and 6.84%, respectively, which were significantly different from that in control group (39.46%). Furthermore, 2 cases of anabiosis and 1 case of live birth were found in D2 undivided group. In arrested development group, there were 55 cases of anabiosis, 11 cases of clinical pregnancy in single-embryo transplantation (including 6 cases of live birth), and 25 cases of clinical pregnancy in combination with one normal embryo transplantation (including 23 cases of live births and 15 cases of dizygotic twins under B-ultrasound). There were 13 case of anabiosis in blastomere reduction group: there was 1 case of single embryo transplantation and clinical pregnancy was obtained; there were also 6 cases of clinical pregnancy in combination with one single normal embryo transplantation (including 5 cases of live births and 2 cases of dizygotic twins under B-ultrasound). In conclusion, embryos with abnormal cleavage rate still have the potential to continue to develop, and have certain blastocyst utilization rate and live birth.