Blastomere cytoplasmic granularity is unrelated to developmental potential of day 3 human embryos

To examine whether the increase in cytoplasmic granularity observed in some human embryos on day 3 of development is of any predictive value as to embryo developmental potential.

Retrospective study comparing outcomes of treatment attempts in three groups of patients after day 3 embryo transfer. Attempts in which only embryos with clear cytoplasm were transferred form Group I, those in which only embryos with granulated cytoplasm were transferred constitute Group II, and Group III consists of cases with mixed transfer combining both types of embryos. Each group was further divided according to the female age.

Clinical pregnancy rates in Groups I (314 attempts), II (173 attempts), and III (323 attempts) were 33.8, 36.4, and 31.3%, respectively. Implantations rates for Groups I-III were 17.0,17.3, and 14.8%, respectively. No significant differences between groups concerning these and other values, including the number of oocytes and of metaphase II oocytes recovered, fertilization and cleavage rates were found. The proportion of good-morphology embryos was also similar between the different groups (74.3, 72.7, and 70.2% respectively). The representation of women of advanced age (>36 years) was also similar in each group, and intergoup differences remained insignificant were only younger or only older women were taken into account.

These data show that the appearance of cytoplasmic granulation in blastomeres of day 3 human embryos is of no prognostic value as to embryo quality and appears to be unrelated to the female age.