Interleukin-6 levels in co-culture of human in vitro fertilization embryoswith vero cells are not predictive of future successful development

PROBLEM: In an attempt to predict successful embryo transfer and implantati on, we measured interleukin (IL)-6 levels in culture supernatants of co-cul tured preimplantation human embryos. We tested whether all in vitro-fertili zed human embryos in co-cultures do secrete IL-6, and whether there was any difference in such production between embryos that successfully reached th e blastocyst stage and blocked embryos. We also addressed the question of I L-G secretion by co-culture support cells, namely Vero cells themselves. METHOD OF STUDY: Each fertilized oocyte was cultured individually and trans ferred in culture wells supplemented with a feeder layer of Vero cells at d ay 2. In vitro IL-G production was measured by bioassay of the culture medi a. RESULTS: Because Vero cells themselves secrete IL-6, it became impossible, in co-culture, to quantify production of IL-G by the sole embryos. On the o ther hand, the co-culture technique has shown us that embryos are likely to consume IL-6. There was no difference between blastocysts and blocked embr yos. CONCLUSIONS: IL-6 levels in human embryo co-cultures do not correlate with future successful embryo transfer.