Correlation of neonatal weight with maternal serum levels of pregnancy-associated plasma protein-A during the first trimester of pregnancy: a retrospective study.

Aim: Evaluate the relationship between neonatal weight and pregnancy-associated plasma protein-A.
Methods: Retrospective study on 2564 singleton pregnancies with healthy term neonates in three groups of women with different values of pregnancy-associated plasma protein-A who underwent the combined test during the first trimester. Non-parametric test and correlation analysis for statistical elaboration were carried out.
Results: There exists a correlation between the serum levels of pregnancy-associated plasma protein-A in the first trimester of pregnancy and neonatal weight. Values of pregnancy-associated plasma protein-A lower than the 25th percentile are associated with neonatal weight in a significant way. There was no significant association between pregnancy-associated plasma protein-A values above 1.50 MoM and neonatal weight.
Conclusion: 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.