#78 : Can Short-Term Insemination with Cumulus Reduction Improve IVF Success?

Background and Aims: Short-term insemination (STI) reduces the exposure time of gametes to accumulation of cell detritus and reactive oxygen species. Thus, our study aimed to explore if the use of STI combined with cumulus reduction (CR) improves IVF success through laboratory measures.

Method: A prospective randomised study was initiated in November 2021. The study group (SG) used STI with a four-hour co-incubation period of oocytes and sperm, inseminated 39 hours post trigger injection. The control group (CG) used standard insemination protocol with 18-hour co-incubation period, inseminated at least 3 hours post trigger injection. Oocytes in both groups underwent CR, were cultured in continuous culture media (Origio 1-Step), undisturbed from fertilisation check to Day 5 (37⁰C, 5% O₂, 6% CO₂).Results were compared by fertilisation, blastocyst formation, day 5 utilisation, overall utilisation, and clinical pregnancy rates (Fisher exact tests).

Results: A total of 152 patients were randomised into the SG while 107 patients were allocated to the CG to February 2023. The STI protocol showed a significant increase in blastocyst formation (SG 71.6% vs CG 63.6%; p<0.05), and rate of day 5 utilisation (SG 88.9% vs CG 80.9%; p<0.05). This far, no differences have been observed in fertilisation (SG 76.2% vs CG 76.5%; p>0.05), overall utilisation (SG 58.8% vs CG 54.1%; p>0.05), nor clinical pregnancy rates (SG 40.0% vs CG 40.5%; p>0.05).

Conclusion: This study reports an increased number of blastocysts, and good quality utilisable day 5 blastocysts when using the STI protocol, with no negative impact to results.Future studies should include the analysis of cumulative pregnancy rates, and live birth rates.