Intracytoplasmic morphologically selected sperm injection outcomes: the role of sperm preparation techniques.

PURPOSE: To compare the results of intracytoplasmic morphologically selected sperm injection (IMSI) between cycles in which the swim-up (SUP) or the density gradient centrifugation (DGC) techniques were used for sperm preparation. METHODS: We evaluated 70 IMSI cycles performed in women with age ≤ 37 years, undergoing IMSI as result of male factor. The couples were divided into two groups: DGC group (n = 26) and SUP group (n = 44). The groups were compared with regard to IMSI outcomes. RESULTS: There were no significant differences between SUP and DGC groups regarding the number of follicles, oocytes, mature oocytes, oocyte yield and mature oocyte rate. Fertilization rate and high-quality embryos rate on day 5 of development were similar between SUP and DGC groups. Implantation, pregnancy and miscarriage rates were not statistically different between SUP and DGC groups (28.8 vs 33.3 %, 46.2 vs 57.1 % and 8.3 vs 4.2 %, respectively). CONCLUSIONS: Both the SUP and the DGC techniques recover improved sperm fractions and result in similar IMSI outcomes. Further randomized trials analyzing both the quality of sperm through MSOME and the IMSI outcomes are needed to elucidate the role of sperm preparation techniques and morphology on IMSI outcomes.