It was performed a case-control study, that included totally 187 pregnant women hospitalized in Obstetrical-Gynecology Department of Prof. Dr. Panait Sarbu Hospital, Bucharest, Romania. The selection criteria for case sample were: age over 30 years, history of malformative risk, clinical exam that emphasised malformations and ultrasound examination that suspicioned embrio-fetal morphological abnormalities. We determined the serum levels of alpha fetoprotein (AFP), human chorionic gonadotropin (hCG) and unconjugated estriol (uE3), by immunoenzymometry. As statistical analysis we determined the estimated median value. For each of the three parametres, the final curve was compared with the value obtained by spectrophotometry. The study revealed the predictive value of correlated use of these three parameters, together with ultrasound examination and cytogenetic investigations, in order to early prenatal diagnosis of congenital fetal anomalies.