Abstract

Measurement of estradiol is useful in women undergoing ovarian stimulation for in vitro fertilization and embryo transfer (IVF-ET). The analytical performance of a new two-step estradiol assay (ADVIA Centaur^® estradiol-6 III from Bayer Diagnostics) was evaluated in 41 sera from 11 women undergoing ovarian stimulation. The results were compared to those obtained with two radioimmunoassays (RIAs; RIA Estradiol Immunotech IM 1663 from Beckmann Coulter and Coat-A-Count Estradiol from Diagnostic Products Corporation) and with one chemiluminescent immunoassay (CLIA; ADVIA Centaur^® estradiol-6). The ADVIA Centaur^® estradiol-6 III assay was the most sensitive assay, with a functional sensitivity of 55 pmol/L. Within- and between-run coefficients of variation calculated for the new ADVIA Centaur^® assay ranged from 3.3% to 9%, which was better than the precision obtained for the other assays. A dilution test showed serum interferences when estradiol was measured in non-diluted samples. No statistical difference was observed between the estradiol results obtained in diluted sera with the new two-step ADVIA Centaur^® assay and those measured with the Immunotech RIA and the other CLIA. In conclusion, this new, two-step estradiol assay performed on the ADVIA Centaur^® system displays suitable sensitivity, precision and intermethod agreement with the Immunotech RIA for the measurement of serum estradiol concentrations in women undergoing ovarian stimulation and IVF-ET. For correct linearity, estradiol measurement should be performed on diluted samples.