Damage of embryo development caused by peroxidized mineral oil and its association with albumin in culture.

OBJECTIVES To examine the effect of free radicals from peroxidized oil and the role of albumin on the passage of radicals. DESIGN Prospective study. SETTING Clinical IVF laboratory and university department. PATIENT(S) Blood samples were donated by laboratory staff. INTERVENTION(S) Examination of the effects of mineral oil samples with various peroxide value (POV) on culture of erythrocytes and on the passage of a lipophilic tracer, DiI, into the zona pellucida. MAIN OUTCOME MEASURE(S) Time required for hemolysis of red blood cells by peroxidized oil, staining of zona pellucida from human oocytes and embryos by lipophilic tracer, and POV analysis of mineral oil samples in relation to various storage conditions. RESULT(S) The time for hemolysis was related to the POV levels of oil samples covering the culture medium. Albumin in the medium facilitated hemolysis and the passage of DiI into the zona. Peroxidized oil (POV >0.02 meq/kg) blocked the entry of DiI into the zona. CONCLUSION(S) The presence of albumin in the medium was associated with the entry into the human zona of agents present in peroxidized mineral oil. This process and variable oil peroxidation could be deleterious to embryos in culture.