From: Prednisone for patients with recurrent implantation failure: study protocol for a double-blind, multicenter, randomized, placebo-controlled trial
Embryo
Scoring system
Criteria of good quality
Blastocyst
Gardner
≥ 4 BC
Cleavage (day 3)
Puissant
7–10 cell 3; 4 or compact
Peter
7–10 cell I; II or compact