Intra- and interobserver analysis in the morphological assessment of early stage embryos during an IVF procedure: a multicentre study oleh Devroe Johanna, Willemen Dorien, Vansteenbrugge Anne, Thonon Fabienne, Wetsels Alex M, Paternot Goedele, Debrock Sophie, D'Hooghe Thomas M, Spiessens Carl