Rimmer, Michael PHowie, Ruth AAnderson, Richard ABarratt, Christopher L.RBarnhart, Kurt TBeebeejaun, YusufBertolla, Ricardo PimentaBortoletto, PietroBrannigan, Robert ECantineau, Astrid E.PCaroppo, EttoreCollura, Barbara LCoward, KevinDuncan, William ColinEisenberg, Michael LGellatly, Steven AGeyter, Christian DeGoulis, Dimitrios GHenkel, Ralf RHo, Vu N.AHussein, Alayman FHuyser, CarinKadijk, Jozef HKamath, Mohan SKhashaba, ShadiKhattak, HajraKobori, YoshitomoKopeika, JuliaKucuk, TansuLuján, SaturninoMatsaseng, Thabo ChristopherMathur, Raj SMcEleny, KevinMitchell, Rod TMol, Ben WMurage, Alfred MNg, Ernest H.YPacey, AllanPerheentupa, Antti HDu Plessis, StefanRives, NathalieSarris, IppokratisSchlegel, Peter NShabbir, MajidŚmiechowski, MaciejSubramanian, VenkateshSunkara, Sesh KTarlarzis, Basil CTüttelmann, FrankVail, Andyvan Wely, MadelonVazquez-Levin, Mónica HLan N. VuongWang, Alex YWang, RuiDuffy, James M.NFarquhar, Cindy MNiederberger, Craig2026-05-202026-05-202025Rimmer, M.P., Howie, R.A., Anderson, R.A., Barratt, C.L., Barnhart, K.T., Beebeejaun, Y., Bertolla, R.P., Bortoletto, P., Brannigan, R.E., Cantineau, A.E. and Caroppo, E., 2025. A core outcome set for future male infertility research: development of an international consensus. Human Reproduction, 40(5), pp.865-875.https://doi.org/10.1016/j.fertnstert.2025.03.009https://hdl.handle.net/10566/22724Objective: To develop a core outcome set for male infertility trials. Design: A two-round Delphi survey and consensus development workshop were undertaken with healthcare professionals, researchers and clinicians globally. Subjects: 334 participants from 39 countries participated in the Delphi Survey, while 44 participants from 21 countries participated in the consensus development workshop. Exposure: NA Main Outcome Measures: The core outcome set for male infertility trials has been developed by the inclusion of specific male-factor outcomes in addition to the general infertility core outcome set which focuses on female-factor outcomes. Results: The outcomes identified include assessment of semen using the World Health Organisation recommendations for semen analysis; viable intrauterine pregnancy confirmed by ultrasound (accounting for singleton, twin and higher multiple pregnancies); pregnancy loss (accounting for ectopic pregnancy, miscarriage, stillbirth and termination of pregnancy); live birth; gestational age at delivery; birthweight; neonatal mortality; and major congenital anomaly. Although not a requirement as part of the core outcome set, other outcomes were identified as potentially useful in certain study settings. Conclusion: Embedding the core outcome set within RCTs and systematic reviews should ensure the comprehensive selection, collection and reporting of core outcomes, which are inconsistently reported at present. Research funding bodies, the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) statement, and over 80 specialty journals, including the Cochrane Gynaecology and Fertility Group, Fertility and Sterility and Human Reproduction, have committed to implementing this core outcome set for male infertility trials.enConsensus development studyCore outcome setsDelphi surveyMale infertilityOutcome measuresArticle