Corrigendum. Do we need to measure progesterone in oocyte donation cycles? A retrospective analysis evaluating cumulative live birth rates and embryo quality. Issue 4 (2nd April 2020) - Racca, A; De Munck, N; Santos-Ribeiro, S; Drakopoulos, P; Errazuriz, J; Galvao, A; Popovic-Todorovic, B; Mackens, S; De Vos, M; Verheyen, G; Tournaye, H; Blockeel, C