Relationship between protein oxidation levels in the follicular fluid and the outcome parameters of in vitro fertilization-embryo transplantation

Objective: To explore the relationship between protein oxidation levels in the follicular fluid and the outcome parameters of in vitro fertilization-embryo transplantation (IVF-ET).

Methods: The levels of advanced oxidation protein products (AOPP) in the follicular fluid were measured in 64 women with tubal infertility undergoing IVF-ET. The relationship between the AOPP levels and IVF-ET outcome parameters was analyzed.

Results: AOPP levels showed significant inverse correlations between the proportion of mature oocytes (r=-0.401, P=0.001), fertilization rate (r=-0.257, P=0.045), cleavage rate (r=-0.290, P=0.024) and good embryo rate (r=-0.520, P=0.000). AOPP levels differed significantly between the groups with different retrieved oocyte numbers (F=3.851, P=0.027), being the lowest in women with 8 to 15 retrieved oocytes and the highest in those with retrieved oocytes below 8. The AOPP level in the non-pregnant women was significantly higher than that in the pregnant women (t=3.665, P=0.001). The AOPP levels also differed significantly with age (F=15.919, P=0.000), and the women >35 years of age had the highest level and those below 30 years had the lowest level.

Conclusions: Protein oxidative stress is present in the follicular fluid of women on IVF-ET cycles. High level of AOPP may have adverse effects on the oocytes and early embryonic development and may affect the outcome of IVF-ET.