[Diagnostic assessment of normal and risk pregnancies. 1. Comparison of two radioimmunological methods for the determination of human placental lactogen (author's transl)].

The HPL-concentrations of 103 plasma samples from normal and 58 samples from risk pregnancies were analyzed with two radioimmunological assay kits from Pharmacia/Freiburg (I) and Ames/Frankfurt (II). Intra- and inter-assay-variation of both methods are similar. The absolute values of HPL-concentrations analyzed by the two methods correspond to a value of about 3.5 microgram/ml (about week 24 of pregnancy). Above this value higher concentrations are analyzed with method II. These differences probably result from use of different standards and different methods of separation of free and bound hormone. Analysis of variance shows a high degree of correlation (r = 0.93, P less than 0.001, n = 147) of the results obtained by both methods.