Interleukin-1 levels in the supernatant of conditioned media of embryos grown in autologous endometrial coculture: Correlation with outcome after in vitro fertilization

Abstract

PROBLEM: To determine if interleukin (IL)-1 produced by autologous endometrial coculture (AECC) was associated with outcome in patients with a history of multiple in vitro fertilization (IVF) failures. METHOD OF STUDY: The conditioned media (CM) from AECC cells exposed or non-exposed to human embryos was analyzed for IL-1. RESULTS: Embryos grown on AECC demonstrated a significant improvement in number of blastomeres and fragmentation (frag) when compared to embryos grown in conventional media without ECC (6.4 ± 1.3 vs. 5.5 ± 1.2 blastomeres and 14.6 ± 9.3% vs. 18.4 ± 9.8% frag; P < 0.008 and 0.003, respectively). When IL-1α and IL-1β were undetectable in the CM, the embryos grown in ECC were of improved quality as compared to the embryos grown only in conventional media. Conversely, IL-1ra levels in the CM were positively associated with embryo quality. Exposure or non-exposure to an embryo did not result in differing levels of IL-1α IL-1β, or IL-1ra in the CM. IL-1β levels were negatively associated with clinical pregnancy outcome (3.3 pg/mL (pregnant, n = 12) vs. 27.1 pg/mL (not pregnant, n = 17); P = 0.008, Mann-Whitney U-test). IL-1α and IL-1ra levels were not associated with outcome. CONCLUSIONS: We have demonstrated a significant improvement in blastomere number and frag with ECC. The presence of IL-1β in the CM was negatively associated with embryonic development and clinical pregnancy. The presence of IL-1α in the CM was negatively associated with embryonic development and the presence of IL-1ra in the CM was positively associated with embryonic development. Whether IL-1β itself interferes with successful outcome after embryo transfer or if it is a marker for undetected endometritis in the biopsy specimens remains to be determined.