Are cytoplasmic strings a really sign of poor embryo quality?

Abstract

Background and Aim: During in-vitro embryo development, trophectoderm (TE) cells project cytoplasmic extensions to the inner cell mass (ICM), known as cytoplasmic strings (CS) or filopodia. CS are mainly classified in two groups: Short strings, which are extended from the ICM to the mural TE and long strings, which are extended from the ICM to the polar ICM. According to bibliography, filopodia are still present during expansion in poor quality blastocysts and related to poor media conditions. On the other hand, some authors claim that CS are not a negative predictor.