Abstract 15837: Decreased Placental Blood Flow in Fetuses With Congenital Heart Disease is Associated With Placental Vascular Abnormalities and Impaired Fetal Growth

Abstract

Introduction: Studies suggest the placenta is abnormal in fetuses with congenital heart disease (CHD), possibly due to shared abnormal vascular developmental pathways. Umbilical venous volume flow (UVVF) is a validated Doppler-derived noninvasive imaging method to assess blood flow from placenta to fetus. We previously demonstrated that mid-gestational UVVF is decreased in fetuses with CHD compared to controls. We hypothesize that decreased UVVF in fetuses with CHD is associated with placental vascular abnormalities as well as impaired fetal growth. Methods: Pregnant women carrying fetuses with CHD (n=38; n=29 single ventricle (SV); n=8 TOF, n=1 d-TGA) or without (n=38) were enrolled in a prospective case-control study. UVVF and combined cardiac output (CCO) were measured during second trimester fetal echocardiograms (echo). Postnatal placentas were analyzed and assigned a placental abnormality severity score (PASS) based on the degree of lesions associated with fetal vascular malperfusion (FVM) and chronic inflammation (CI). Biometrics were collected for all newborns. T-tests or Fisher’s Exact tests were performed to assess statistical significance. Results: Gestational age (GA) at time of fetal echo was slightly greater for the CHD group (Table). All CHD fetuses as well as subgroup analysis of SV only had decreased UVVF indexed to fetal weight (UVVF/Wt) and to CCO (UVVF/CCO). Placental PASS analysis demonstrated higher grade FVM and CI lesions in fetuses with CHD. Fetuses with CHD were born earlier and had decreased birth weight z-scores compared to controls. Conclusions: Fetuses with CHD demonstrate decreased placental blood flow in utero, higher grade placental lesions associated with FVM and CI, and decreased birth weight. UVVF reflects characteristics of abnormal placental pathology and may be a useful marker of placental malperfusion in fetuses with CHD. Future study looking at association of UVVF and clinical outcomes is warranted.