Abstract: The present invention relates to a method for an early stage detection of three specific pregnancy-related disorders: preeclampsia, intrauterine growth retardation and preterm delivery. According to the method, an antigen consisting of a specific human-derived placental soluble protein, known as PP-13, is determined by radioimmunoassay or ELISA. In the radioimmunoassay method, the PP-13 is labelled by a radioactive iodine and the bounded iodine is counted and correlated with standard curves. The best results are obtained when the protein to be labelled by radioactive iodine is present at a concentration of above 0.71 mg/ml. In case of the ELISA method, the quantitative determination of PP-13 is carried out with an alkaline phosphatase substrate and measured at an optical density of 405 nm.