Serum progesterone and estradiol levels were measured three times during the mid and late luteal phase (on the 4th, 7th and 11th day after ET). In addition, progesterone levels were also measured on the ET day, following our routine clinical practice. Blood was drawn 6 hours after last insertion of vaginal P. Hormonal measurements were blinded, and the results were not available until the end of the study.
Blood samples were analyzed by an electrochemiluminescence immunoassay (CobasVR e411 analyzer, Roche diagnostics GmbH, Germany). Intra- and inter-assay coefficients of variation for the P determinations were 1.2–11.8% and 3.6–23.1%, respectively, for P-values between 0.22 and 51.6 ng/ml. Sensitivity was 0.03 ng/ml. The intra- and inter-assay coefficients of variation for estradiol determinations were 2.4–9.5% and 2.5–11.9%, with a measurement range of 25.4–2932 pg/ml. Sensitivity was 5 pg/ml.
Elecsys HCG+β was analyzed at Roche Diagnostics using a CobasVR e 411 analyzer, with a functional assay sensitivity of <0.6 mIU/ml.
Blood samples were analyzed by an electrochemiluminescence immunoassay (CobasVR e411 analyzer, Roche diagnostics GmbH, Germany). Intra- and inter-assay coefficients of variation for the P determinations were 1.2–11.8% and 3.6–23.1%, respectively, for P-values between 0.22 and 51.6 ng/ml. Sensitivity was 0.03 ng/ml. The intra- and inter-assay coefficients of variation for estradiol determinations were 2.4–9.5% and 2.5–11.9%, with a measurement range of 25.4–2932 pg/ml. Sensitivity was 5 pg/ml.
Elecsys HCG+β was analyzed at Roche Diagnostics using a CobasVR e 411 analyzer, with a functional assay sensitivity of <0.6 mIU/ml.