Conventional IVF versus ICSI in sibling oocytes from couples with endometriosis and normozoospermic semen

Purpose: This study compares the fertilization rate and embryonic development of oocytes randomly inseminated by conventional IVF or ICSI in patients with endometriosis and normozoospermic semen during IVF cycles. Methods: Sibling oocytes were randomized to be inseminated either by ICSI or IVF. Rates of fertilization, cleavage, blastulation and embryonic morphology were assessed. Results: A total of 786 sibling cumulus-oocyte complexes (COC) were randomized between insemination by conventional IVF (387 COC) or ICSI (399 COC). A significantly higher fertilization rate was found in the ICSI group (ICSI versus IVF, 73.3±23 % versus 54.7±31.9 % respectively; P=0.003), yielding a higher mean number of day 2 embryos (5.2±3.4 versus 3.6±2.9 respectively; P=0.002). Triploid fertilization rate (3PN/COC) was significantly higher in the IVF group compared to the ICSI group (3.9±8.7 % versus 0.9±3.1 % respectively; P=0.02). The morphology score and rate of development of day 2 and 3 embryos were not different between the two groups. Comparison of embryo transfer cycles in which either IVF or ICSI only embryos were transferred did not reveal any statistically significant differences in pregnancy or implantation rates. Conclusion: ICSI appears to be a better treatment option than conventional IVF in endometriosis-associated infertility, since it offers the advantages of higher fertilization rate and mean number of embryos and lower rate of total fertilization failure and triploid fertilization.