Influence of Weight of Pregnant Women on First Trimester Biochemical Markers Values

Abstract

Values of first trimester biochemical markers (PAPP-A and free b-hCG) concentration are included in aneuploidies risk evaluation algorithm. Since both markers are produced by the fetus and placenta their concentration depends on the volume in which they are dissolved, respectively the weight of the pregnant women. Our study aimed to analyze the influence of maternal weight on first trimester biochemical markers concentration and the ability of the risk calculation software to correct this influence. Pregnancy-associated protein A (PAPP-A) and free � chorionic gonadotropin hormone (free � hCG) first trimester sera concentration respectively weight were measured in 1629 pregnant women. First trimester PAPP-A and free beta hCG concentrations inverse correlate with weight of pregnant women rho=-0.33, p[0.0001, respectively rho=-0.18, p[0.0001. Weight of pregnant women inversely correlates with multiple of median (MoM) values of first trimester markers too: rho=-0.38, p[0.0001 (PAPP-A), respectively rho=-0.17, p[0.0001 (free-b-hCG). The software counterbalances the influence of weight on biochemical markers values. PAPP-A corrected MoM (MoMc) values don�t inversely correlate with the weight (rho=-0.03, p=0.12), whereas free � hCG MoMc values showed an extremely weak inverse correlation (rho=-0.08, p=0.0008). The software counterbalances the influence of weight on PAPP-A values, whereas an extremely weak but insignificant inverse correlation between weight and free-beta hCG values persists after correction.