The Best of ASRM and ESHRE is a continuing medial education (CME) programme inteded to present evidence for both established and emerging approaches to the science and art of reproductive healthcare, with faculty from ASRM and ESHRE aiming to compare glabal approaches and technologies for diagnosis and treatment. The programme for 2021 thus brings together plenary and cutting-edge sessions on ovarian ageing, donor anonymity (the end of), gene therapies in male infertility, in vitro maturation, synthetic 'gametes', biological sensors of in-utero monitoring, and obesity in reproductive funtion. Debates back-to-back sessions include opposing views on recurrent implantation failure, social egg freezing, pretreatment scheduling in IVF, finbroids in IVF, dual stimulation, PGT-A, thrombophilia in IVF, severe male factor infertility, and the decline of cleavage-stage embryo transfer. The meeting thus offers a unique opportunity to hear views on hot topics from both sides of the Atlantic and keep up-to-date with how opinions may or may not diverge.