+44 20 3868 9735
Kyle J Tobler, Paul Brezina, Jairo E Garcia and Yulian Zhao
Background: To determine the difference in fertilization and blastulation rates between sibling oocytes randomly assigned to either Conventional Fertilization (CF) or Intracytoplasmic Sperm Injection (ICSI) in patient couples with normal semen analysis parameters.
Methods: A retrospective review of embryologic and clinical outcomes from patients undergoing their first In Vitro Fertilization (IVF) cycle that randomly assigned one-half of sibling oocytes to either CF or ICSI. Randomization occurred prior to removal of the oocyte cumulus cells which allows identification of metaphase II oocytes eligible for ICSI. All male partners met normal semen analysis parameters and normal fertilization was anticipated for the IVF cycle. Each patient served as their own control.
Results: A total of 682 oocytes were included and were assigned to either CF or ICSI. The CF had a significantly higher fertilization rate compared to ICSI (67.9% versus 60%) when immature (non-metaphase II) oocytes were included in the analysis; however this difference diminished when only those oocytes eligible for ICSI were included. There was no difference in the day-3 embryo progression, the blastulation rate, the mean number of oocytes fertilized and the mean number of blastocysts per IVF cycle. Additionally, there was no significant difference in the pregnancy related outcomes between the two groups.
Conclusions: These studies demonstrates that in patient couples with normal semen analysis parameters, undergoing their first IVF cycle and who have anticipate normal fertilization, randomly assigning oocytes to CF or ICSI does not improve fertilization or blastulation. To confirm these findings, larger prospective studies are required.