This study evaluated the effect of sperm selection and intracytoplasmic sperm injection (ICSI) on subsequent fertilization and embryo development using the hyaluronic acid-based SpermSlow™ (HA-ICSI) compared to injection with polyvinylpyrrolidone (PVP-ICSI). A total of 206 metaphase II oocytes were collected from 21 prospectively enrolled ICSI cycles at Fertility North between July 2014 and March 2015. Sibling oocytes were randomized into HA-ICSI and PVP-ICSI (n = 103 per group). Subsequent fertilization outcomes and embryo development in terms of qualitative and quantitative time-lapse measures following three-day culture in the Embryoscope™ were compared. HA-ICSI resulted in significantly lower abnormal fertilization rates (1.9% vs 9.7%, p = 0.017), and a trend towards increased normal fertilization rates (73.8% vs 62.1%, p = 0.073) with increased injection time (2.5 vs 2.1 min, p = 0.001). No differences between HA-ICSI and PVP-ICSI were observed in (a) the proportion of good conventional morphology embryos (50% vs 53.1%, p = 0.712), (b) time-lapse qualitative measures (p > 0.05) and (c) time-lapse quantitative measures (p > 0.05). In conclusion, HA-ICSI improves fertilization outcomes although sperm injection takes longer to complete. Subsequent embryo development up to day 3 is not affected.
Keywords: Intracytoplasmic sperm injection (ICSI); embryo culture; spermatozoa.