Setting standards for the levels of endotoxin in the embryo culture media of human in vitro fertilization and embryo transfer

Objective: To clarify the optimum set standards for the levels of endotoxin in a culture medium for human IVF-ET programs. Design: Retrospective and randomized study. Setting: One hundred patients underwent 163 cycles of IVF-ET at Fukuoka University Hospital. Interventions: Measurements for endotoxin were performed using the Limulus Amoebocyte Lysate test, The negative group was administered media with <1 pg/mL of endotoxin and the positive group was given media with greater than or equal to 1 pg/mL of endotoxin. Main Outcome Measures: Human embryo development, clinical outcomes, and pregnancy outcomes were evaluated in each group and also the levels of endotoxin. Results: The rates of clinical pregnancy (26.1%) and the live birth rates (20.7%) in the negative media were significantly higher than those in the positive media (9.9% and 5.6%, respectively). Rates of embryo development were decreased and a gestational sac and fetal heart beat were not detected in media with >2 pg/mL of endotoxin. Conclusion: The set standard for the level of endotoxin in a medium should be <1 pg/mL to obtain the best outcome. The allowable levels of endotoxin in a medium should be less than or equal to 2 pg/mL in human IVF.