Predictive value of pregnancy-associated plasma protein-A (PAPP-A) and free beta-hCG on fetal growth restriction: results of a prospective study.

Purpose: Low levels of plasmatic pregnancy-associated plasma protein-A (PAPP-A) and high levels of free-beta human chorionic gonadotropin (beta-hCG) could influence the outcome of pregnancy. The objective of this study is to assess the correlation between PAPP-A and free beta-hCG and birth weight.

Materials And Methods: Prospective follow-up study performed on 3332 patients in the first trimester of pregnancy who were subjected to a screening test focused on evaluation of fetal aneuploidy (SCA-TEST). The values of PAPP-A and free beta-hCG were both analyzed as raw values and subsequently converted to a multiple of the median (MoM). Statistical analysis was performed using SPSS version 17.0.1 (SPSS Inc., Chicago, USA).

Results: The incidence of "small for gestational age" in patients with PAPP-A MoM <1st and <5th ‰ was statistically significant (12 and 9.8 %; p < 0.0001). Also statistically significant data have been highlighted about free beta MoM > 95th ‰ (7 %; p = 0.03). The values of PAPP-A MoM > 99th ‰ are significantly correlated with an increased risk of "large for gestational age" (16.7 %; p < 0.0001).

Conclusion: Our study demonstrates that specific values of PAPP-A and free beta-hCG could identify the risk of low or high birth weight since the first trimester of pregnancy.