*4.5. Hormones Immuno Assays*

As previously described [11], total hCG and P4 concentrations were determined in supernatants of culture using ECLIA immuno-assay (Liaison®, DiaSorin, Sallugia, Italy). Measuring ranges of both assays were respectively of 1.5–10,000 UI/L and of 0.7–190 nmol/L. Between assay precision expressed by the coefficient of variation (CV %) were <5% and <11% and detection limits were 0.3 UI/L and 0.4 nmol/L respectively.
