RESUMO
STUDY QUESTION: Is ICSI better than conventional IVF for non-male factor infertility? SUMMARY ANSWER: IVF should be the choice of assisted reproductive technique in non-male factor infertility cases. WHAT IS ALREADY KNOWN: Although total fertilization failure is a major concern for patients and professionals, the overall risk/benefit analysis favors conventional IVF in non-male factor infertility cases. However, according to the ESHRE EIM database pertaining to 1997-2012, the use of IVF has been continuously decreasing in favor of ICSI. STUDY DESIGN, SIZE, DURATION: Randomized controlled double-blind study involving 138 women undergoing ART in a private Center. PARTICIPANTS/MATERIALS, SETTING, METHODS: All couples with a female partner ≤42 years of age and without severe male factor (total progressive motile sperm with normal morphology >10.000) were included in the study. Exclusion criteria were: history of total fertilization failure, less than 6 cumulus oocyte complexes (COC) available for fertilization, prenatal genetic testing (PGT) cycles, unwillingness to participate and couples undergoing total cryopreservation for any indication. On the day of oocyte pick up, sibling COCs were randomly allocated to fertilization with IVF or denudation followed by ICSI to MII oocytes. The decision to transfer IVF or ICSI embryo(s) depended on embryo quality. Women receiving two embryos were given only IVF or ICSI embryos. Neither the clinician performing the transfer nor the patients were aware of the fertilization method used to generate the embryos transferred. Main outcome parameters were fertilization, clinical pregnancy, implantation and miscarriage rates. MAIN RESULTS AND THE ROLE OF CHANCE: Demographic variables, ovarian reserve and infertility etiology, duration of stimulation, total gonadotropin consumption, peak estradiol levels were similar for IVF-ET and ICSI-ET groups. Mean number of COCs (18.95 vs 19.24), number of embryos transferred (1,81 vs 1,81), the ratio of good quality embryos/total embryos (56.89 % and 55.97 %), clinical pregnancy rates (63 % vs 49 %), implantation rates (31 % vs 28 %), and abortion rates (12,5 % vs 8,1 %) were also similar. A total of 1306 COCs were allocated for IVF while 1331 COCs were denuded for ICSI. Fertilization rate per inseminated oocyte was significantly higher in ICSI group (56,20 % vs 63,78 %). There were ten cases of total fertilization failure, all in the IVF group. Although overall fertilization rate was higher for ICSI, it was similar in both groups when cases with total fertilization failure were excluded. LIMITATIONS, REASONS FOR CAUTION: The non-availability of live birth rates is a limitation. Randomization of sibling oocytes, not patients requires careful interpretation of pregnancy and implantation rates. WIDER IMPLICATIONS OF THE FINDINGS: Lower cost, ease of application and similar clinical outcome makes IVF the choice of fertilization method in non-male factor infertility cases.