Debate: Are We Limiting the Potential of Oocytes by Not Using ICSI for All? - ICSI Should be Used for Most IVF Cycles

Abstract

Background: Following earlier studies introducing an IVF-ICSI Split model on couples with unexplained infertility to avoid the scenario of unexplained failed or poor fertilization, PIVET has adopted a high ICSI rate approaching 90%, whereas the general rate among Australian facilities is around 60%. Aim: To compare the embryology and clinical outcomes in an IVF program where ICSI is applied beyond male-factor reasons and applies an IVF-ICSI Split protocol for IVF-naïve women with unexplained infertility. Method: This observational study with retrospective data analysis reports on autologous IVF± ICSI procedures conducted over the period 2011 to 2019 with follow-up of ensuing pregnancies through 2020. Results: Using autologous oocytes, 2343 women had 3434 IVF± ICSI cycles with 84.5% of women had 88.9% of initiated treatment cycles using ICSI and only 5.3% of women had 4.0% of cycles by IVF. The remaining 10.1% of women utilised the IVF-ICSI Split model for the remaining 7.2% of cycles. It was shown that oocyte fertilisation rates were significantly higher for ICSI (p<0.0001), but not significant for women >40 years. The utilisation rates of the ensuing embryos were [Formula: see text]45% across all ages with no significant differences across the ages, except for those small numbers of women [Formula: see text] 45 years who had a higher rate from IVF-generated embryos (p<0.0002). Pregnancy outcomes were higher from ICSI-generated embryos across the age groups, being especially marked among the younger women <40 years (p<0.0001). Miscarriage rates were lowest for the IVF-generated pregnancies (overall 6.7% vs 22.8%, p<0.0001) but nevertheless the final live birth productivity rates per initiated treatment cycle remained higher from the ICSI-generated pregnancies (56.5% vs 46.3%; p<0.0001). Conclusion: Although this study does not meet the highest standards for EBM, it emanates from a pioneer facility with >40 years of published activity and which practices 90% blastocyst transfers in >90% SET cycles. The study supports a high ICSI rate of 90% and an IVF-ICSI Split rate of 10%.