Microfluidic preparation of spermatozoa for ICSI produces similar embryo quality to density-gradient centrifugation: A pragmatic, randomized controlled trial

Abstract

STUDY QUESTION: Does processing of spermatozoa for IVF with ICSI by a microfluidic sperm separation device improve embryo quality compared with density-gradient centrifugation? SUMMARY ANSWER: Patients randomized to microfluidic sperm preparation had similar cleavage-and blastocyst-stage embryo quality and clinical and ongoing pregnancy rates to those who underwent standard sperm processing for IVF with ICSI. WHAT IS KNOWN ALREADY: Microfluidic sperm preparation can isolate spermatozoa for clinical use with minimal DNA fragmentation but with unclear impact on clinical outcomes. STUDY DESIGN, SIZE, DURATION: A prospective randomized controlled trial of 386 patients planning IVF from June 2017 through September 2021 was carried out. PARTICIPANTS/MATERIALS, SETTING, METHODS: One hundred and ninety-Two patients were allocated to sperm processing with a microfluidic sperm separation device for ICSI, while 194 patients were allocated to clinical standard density-gradient centrifugation (control) at an academic medical centre. MAIN RESULTS AND THE ROLE OF CHANCE: In an intention to treat analysis, there were no differences in high-quality cleavage-stage embryo fraction [66.0 (25.8)% control versus 68.0 (30.3) microfluidic sperm preparation, P = 0.541, absolute difference-2.0, 95% CI (-8.5, 4.5)], or high-quality blastocyst fraction [37.4 (25.4) control versus 37.4 (26.2) microfluidic sperm preparation, P = 0.985, absolute difference-0.6 95% CI (-6, 5.9)] between groups. There were no differences in the clinical pregnancy or ongoing pregnancy rates between groups. LIMITATIONS, REASONS FOR CAUTION: The population studied was inclusive and did not attempt to isolate male factor infertility cases or patients with a history of elevated sperm DNA fragmentation. WIDER IMPLICATIONS OF THE FINDINGS: Microfluidic sperm separation performs similarly to density-gradient centrifugation in sperm preparation for IVF in an unselected population. STUDY FUNDING/COMPETING INTEREST(S): No external funding to declare. M.P.R. is a member of the Clinical Advisory Board for ZyM?t® Fertility, Inc. TRIAL REGISTRATION NUMBER: NCT03085433. TRIAL REGISTRATION DATE: 21 March 2017. DATE OF FIRST PATIENT'S ENROLLMENT: 16 June 2017.