EP14.25: Placental weight and volume related to birthweight and third trimester maternal blood sample in normal and IUGR pregnancies

Abstract

Studies have reported placental weight ratio (PWR) and maternal hemoglobin (Hgb) as relevant markers of uteroplacental function. Our aim was to investigate the correlations among maternal hemostasis, placental morphology, birth weight and ultrasonographic findings in normal and IUGR pregnancies. 13 patients were recruited into the case group based on their newborn's weight being below the 10th percentile and 41 patients were enrolled randomly. The placental weight and volume were measured and data were compared with the third trimester maternal blood sample. PWR results were close to that described in literature, 0.14(±0.004) in the control and 0.17(±0.01) in the IUGR group p=0.0034. In placental morphometry placental volume showed the strongest correlation (R2=0.769), while a. umbilicalis S/D (R2= 0.538) and Hgb level (R2=0.510) showed medium correlation and placental weight showed light correlation (R2=0.446) with birthweight. There was significant difference between the control and IUGR groups in birthweight 3367.73g(±71.52) and 2110.04g(±155.7) p=0.0001, in a. umbilicalis S/D 2.217(±0.107) and 3.388(±0.309) p=0.0006, in placental volume 523.0cm3(±33.43) and 311.7cm3(±23.73) p=0.0007 and in placental weight 483.4g(±17.89) and 391g(±28.00) p=0.0364 respectively. We found no significant difference in gestational age, gender ratio, MCV, red blood cell count, hematocrit, thrombocyte count, INR, and partial thromboplastin time. IUGR is a diagnostic challenge because fetal biometry has a 50% detection rate. Our results show that placental volume is more concordant with birthweight than placental weight. The estimation of placental volume via ultrasound could complete fetal biometry and a. umbilicalis flowmetry in diagnostic routine. These measurements could increase the accuracy of prediction of pregnancy outcome. We do encourage clinics and investigators to establish a percentile chart for placental volume.