Improved embryonic development and utilization rates with EmbryoScope: a within-subject comparison versus a benchtop...

The objective of this study was to investigate whether, in consecutive intracytoplasmic sperm injection (ICSI) cycles, embryonic development in an incubator with a time-lapse imaging (TLI) system is better than the previous one obtained in a benchtop incubator (G-185) with similar cultivation characteristics. The study was of a retrospective within-subject design, in which each cycle served as its own control. Data were obtained via the chart review of patients undergoing ICSI in a private university-affiliated in vitro fertilization (IVF) centre who fulfilled the following criteria: second ICSI attempt in which embryos were cultured in a TLI incubator system (TLI group, n = 71), preceded by a first ICSI attempt in which embryos were cultured in a benchtop incubator (Control group, n = 71). Embryonic development up to the fifth day of development, oocyte utilization rate (OUR; transferred embryos plus frozen embryos per total number of retrieved oocytes) and embryo utilization rate (EUR; transferred embryos plus frozen embryos per normally fertilized oocyte) were compared between the groups. There were significant differences in the day 2 non-cleavage rate, day 5 embryo rate, blastocyst development rate, frozen blastocyst rate, OUR, and EUR, in favour of the TLI group. Embryonic development, frozen blastocyst rate, OUR and EUR in the second ICSI cycle were significantly improved when the culture was performed in the EmbryoScope, compared with those rates obtained with culture in a G-185 in the first ICSI cycle of the same patients. The results may also lead to higher cumulative pregnancy outcomes following embryo thawing and transfer.