P-251 Differences in fertilization, blastocyst, and ploidy rates in intracytoplasmic sperm injection (ICSI) versus conventional insemination for patients undergoing in vitro fertilization (IVF)

Abstract Study question Are there differences in fertilization, blastocyst development, or euploidy rates when comparing ICSI versus conventional insemination among patients with male and non-male factor infertility? Summary answer Fertilization rate was lower for male factor ICSI. There were no differences in blastocyst development. Euploidy rate was lower for non-male factor ICSI. What is known already ICSI was developed for male factor infertility due to its requirement for a very small number of viable sperm. Its use has expanded beyond male factor due to some studies suggesting enhanced fertilization, and lower risks of failed fertilization or inadvertent contamination of embryo biopsy specimens. There are potential risks associated with ICSI, including imprinting disorders, birth defects, and significantly increased cost. It is also unclear whether ICSI contributes to genetic abnormalities by bypassing the egg’s natural sperm selection and potentially disrupting the meiosis apparatus. Study design, size, duration This retrospective cohort study of 576 patients was conducted at a single clinic from January 2021 to December 2021. Patients were grouped into (1) ICSI with male factor (n = 201), (2) ICSI with non-male factor (n = 160), and (3) conventional insemination with non-male factor (n = 215). Primary outcome was ploidy status, determined by calculating the percentage of euploid, aneuploid, and mosaic (both low and high mosaic) among the three groups. Secondary outcomes included fertilization and blastocyst development rates. Participants/materials, setting, methods Patients undergoing autologous IVF at a single clinic, with PGT-A performed at a single lab were included. Fertilization rate was defined as the percentage of 2PNs per number of mature eggs injected/inseminated. Blastocyst rate was defined as the percentage of blastocysts per 2PNs. Ploidy rate was defined as the percentage of euploid/aneuploid/mosaic blastocysts per total biopsied blastocysts for which a result was obtained. Percentage data was compared using N-1 Chi-squared test. Main results and the role of chance There were no significant differences in patient age, number of oocytes retrieved, or number of mature oocytes among the three groups. Fertilization rate for male factor ICSI was significantly lower compared to both non-male factor ICSI (74.2% vs 77.8%, p = 0.005) and conventional insemination (74.2% vs 76.8%, p = 0.018). There was no significant difference in fertilization