EP18.06: Correlation between placental angiogenic biomarkers, placental weight and placental vascular lesions in women with pre‐eclampsia

Placental angiogenic biomarkers soluble FMS-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) are implicated in the pathogenesis of pre-eclampsia (PE) and intrauterine growth restriction (IUGR), characterised by placental dysfunction. The aim of this study is to study the link between maternal serum placental biomarkers, placental weight and placental vascular lesions. In a retrospective cohort of 108 pregnancies between 2018-2021, serum sFlt-1, PlGF and sFlt-1/PlGF ratio were analysed in relation to placental characteristics, e.g. placental weight, placental weight/birthweight ratio and presence of maternal and fetal vascular malperfusion (MVM and FVM) lesions. Linear correlations were tested using Spearman's correlation. Women with PE had more frequent abnormal sFlt-1/PlGF ratio >38 compared to women with normal pregnancies (46% vs. 32%, p = 0.007), and a higher sFlt-1/PlGF ratio and (51.42 vs. 1.60, p < 0.001), but here was no difference in the placental weight/birthweight ratio (14.8 vs. 16.7, respectively, p = 0.09), nor in coiling index (0.20 vs. 0.22, respectively, p = 0.9). There was a mild linear correlation between sFlt-1/PlGF ratio and placenta weight percentile (r= -0.54, p < 0.001). but no correlation with placental weight/birthweight ratio, nor with umbilical cord coiling index and prevalence of MVM or FVM lesions. Although maternal biomarker concentrations are strongly linked to clinical outcomes in women with PE and IIUGR, and possibly also to placental weight, these data suggest that biomarkers are not predictive of the development of pathological vascular lesions in the placenta.