Objective: To examine the effect of human embryo coculture with an ovarian cancer cell line.
Design: Prospective, randomized in vitro study.
Setting: University of Toronto IVF clinic at The Toronto Hospital.
Patients: Couples undergoing IVF who chose not to cryopreserve their spare embryos and were willing to donate spare embryos for research.
Intervention: Spare embryos were cultured randomly either under regular conditions with Ham's F-10 medium supplemented with 10% heat inactivated human serum (n = 189) or were cocultured in the same medium, with human ovarian epithelial cancer cells (n = 173).
Main outcome measure: Blastocyst formation.
Results: Coculture with the cancer cell line improved the preimplantation embryo development to the blastocyst stage. There was a significant increase in the number of cavitating morulae (68%) and the proportion of embryos reaching the fully expanded blastocyst stage (39%) compared with those in standard culture medium (34% and 23%, respectively).
Conclusion: Coculture of early cleavage stage human embryos with epithelial cancer cells markedly improves in vitro human blastocyst formation compared with standard culture conditions.