CG Petersen, AL Mauri, R Ferreira, R L R Baruffi, JG Franco Jr.
JBRA Assist. Reprod. 1999; 3 (3):7-13
Received April 23, 1999
Accepted October 16, 1999
Abstract
Early embryo selection (EES ) criteria have been extensively discussed. The following EES criteria were studied: I- oocyte and zygote characteristics (cytoplasmic granulation waves; pronucleus (PN) migration, junction and alignment; number and polarization of nucleoli; a light halo at the cytoplasmic end. II- Early cleavage (EC); III- morphology (symmetrical blastomeres with l ow fragmentation and absence of multinucletion); IV - cleavage rate. Literature data have proved that EES after ICSI is efficient when based on EC and on the presence of 4-cell embryos. However, although little studied, parameters concerning the zygote also indicate the sarne tendency. Analysis of the literature suggests that the sum of several criteria should be used for EES after ICSI, perhaps in the form of a gradual development score from oocyte to embryo
