Coculture with ovarian cancer cell enhances human blastocyst formation in vitro

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.