Development of human embryos to the hatched blastocyst stage in the presence or absence of a monolayer of Vero cells

Abstract

In a prospective randomized study, excess embryos from 100 women undergoing in-vitro fertilization were cultured from the 2-cell to the hatched-blastocyst stage in the presence or absence of a confluent monolayer of Vero cells. The frequencies of fragmentation, developmental arrest, multinucleation and blastocyst formation were observed for 254 embryos over 7 days in culture. The number of nucleated cells, and fine structure of trophectoderm and inner cell mass were analysed at the expanded blastocyst stage on day 5.5 post-insemination. The frequency of hatching from the zona pellucida was determined between days 6 and 7 post-insemination. With respect to these developmental parameters, the findings indicate that no overt or statistically significant improvement in early human embryogenesis occurs in the co-culture system.