Abstract
PURPOSE: Limited research has been published comparing PIEZO-ICSI with conventional ICSI. While positive effects have been documented in improving fertilization and degeneration, the outcomes in patients with previous poor results from conventional ICSI remain unclear. It is hypothesized that these patients may benefit the most from this form of insemination. METHODS: This retrospective paired within-patient cohort study investigated patients (n=72) undertaking PIEZO-ICSI after a previous conventional ICSI cycle resulted in poor outcomes (including low fertilization (<50%), high degeneration (>15%), and/or poor embryo development and utilization). Patients required at least five oocytes collected in both cycles and a period of less than 2 years between the cycles. The outcomes of both cycles were compared in respect to fertilization, degeneration, embryo utilization, and pregnancy rates. Further analyses were applied to patients <38 and ≥38 years of age, with <50% or ≥50% fertilization with conventional ICSI and with <20% or ≥20% utilization with conventional ICSI. RESULTS: PIEZO-ICSI resulted in significantly higher fertilization (61.9% vs 45.3%, P<0.0001) and lower degeneration (7.7% vs 18.2%, P=0.0001) when compared to the conventional ICSI cycles. The greatest benefit was seen in patients who had less than 50% fertilization or <20% utilization in their conventional ICSI cycle, with improvements in fertilization and degeneration rates resulting in a significantly higher number of embryos utilized (frozen or transferred) per cycle. CONCLUSIONS: PIEZO-ICSI improved fertilization, degeneration, and utilization rates in patients with previous poor outcomes from conventional ICSI. The number of embryos available for use per cycle was also increased. Further significant improvements were achieved in patients who exhibited poor fertilization (<50%) or low utilization (<20%) from conventional ICSI.