BMJ Open, 11(1):042395. BMJ PUBLISHING GROUP BMJ Open, 11(1):e042395. BMJ Publishing Group BMJ open, 11(1):e042395. BMJ Publishing Group BMJ Open, 11(1):042395. BMJ Publishing Group BMJ Open BMJ Open, 11 Cornelisse, S, Ramos, L, Arends, B, Brink-van der Vlugt, J J, de Bruin, J P, Curfs, M H J N, Derhaag, J, van Dongen, A, van Echten-Arends, J, Groenewoud, E R, Maas, J W M, Pieterse, Q, van Santbrink, E J P, Slappendel, E, Traas, M A F, Visser, J, Vergouw, C G, Verhoeve, H R, van der Westerlaken, L A J, Wurth, Y, van der Zanden, M, Braat, D D M, van Wely, M, Mastenbroek, S & Fleischer, K 2021, ' Comparing the cumulative live birth rate of cleavage-stage versus blastocyst-stage embryo transfers between IVF cycles: A study protocol for a multicentre randomised controlled superiority trial (the ToF trial) ', BMJ Open, vol. 11, no. 1, e042395 . https://doi.org/10.1136/bmjopen-2020-042395 BMJ Open, 11, 1 BMJ Open, Vol 11, Iss 1 (2021)