This study confirms the positive correlation between circulating concentrations of pregnancy-associated plasma protein-A and fetal growth. Low neonatal weight and factors that can cause this could be determined from the first trimester by measuring the concentrations of pregnancy-associated plasma protein-A in maternal serum. Even if the association between the levels of pregnancy-associated plasma protein-A and a low neonatal weight has been demonstrated, however, we have to say that the sensitivity of a such screening method for the prediction of low birth weight and perinatal complications seems to be rather low. The variations of pregnancy-associated plasma protein-A during the first trimester cannot be used as a marker of excessive fetal growth.