Cumulative live birth rates in ICSI cycles with donated oocytes are not improved by magnetic-activated cell sorting: A retrospective study in unselected males

Published:October 07, 2021DOI:


      • Magnetic-activated cell sorting (MACS) is a successful tool to remove apoptotic sperm
      • There is a lack of consensus on the clinical relevance of MACS in ART
      • The use of add-ons in ART should always be based on well contrasted clinical evidence
      • MACS before ICSI with donated oocytes slightly improved CLBR per embryo transferred
      • It was not sufficiently meaningful to recommend the use of MACS to all these patients


      Research question

      Does magnetic-activated cell sorting (MACS) increase cumulative live birth rates (CLBRs) or improve clinical parameters of reproductive success in couples undergoing ICSI with donor oocytes?


      Retrospective multicenter observational study. Data were compiled from unselected couples who underwent ICSI cycles with donated oocytes in fifteen Spanish IVIRMA fertility clinics (January 2008 to Feb 2020). Patients were divided into reference (standard semen processing, n=40,103) and MACS (additional sperm selection step by MACS, n=900) groups. CLBRs were plotted in Kaplan-Meier curves and compared using the Mantel-Cox test. Proportions were compared with Fisher's exact test. A mixed-effects logistic regression model was developed to adjust results to clinically relevant variables.


      The MACS group showed a 27.1% CLBR after one embryo was replaced and 81.6% after four; the reference group had CLBRs of 19.6% and 78.5%, respectively. CLBR in the MACS group was 4.2% after five oocytes were used and 75.5% after fifteen; for the reference group, CLBRs were 7.8% and 78.3%, respectively. Differences between Kaplan-Meier curves of each group were statistically significant for both measurements. No significant differences between the groups were found in terms of CLBR per embryo transfer (ET) or in classical clinical outcomes such as pregnancy and live birth rates per ET.


      Even though MACS sperm selection slightly increased the cumulative live birth rate per embryo transferred compared to the reference group, this change was not clinically meaningful. MACS should not be recommended indiscriminately to all infertile patients undergoing ICSI with donated oocytes as a sperm processing add-on.

      Graphical abstract


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      María Gil Juliá is a predoctoral researcher of the Andrology and Male Infertility group at IVI Foundation. She obtained a MSc in Biotechnology of Human Assisted Reproduction by the Universidad de Valencia in 2020 and a MRes in Biomedical Research by Imperial College London in 2018.
      Key message
      Non-apoptotic sperm selection by MACS before ICSI with donor oocytes slightly increased cumulative live birth rates per embryo transferred, though this was not clinically meaningful. Thus, MACS should not be recommended to all infertile couples undergoing ICSI with donor oocytes as a generic approach to improving reproductive outcomes.