EP09.11: Cord blood cardiovascular biomarker profile in Fallot fetuses and its correlation with the severity of right ventricle outflow tract obstruction

To describe the cord blood profile of cardiovascular biomarkers in fetuses with tetralogy of Fallot (ToF) and to explore its correlation with fetal echocardiography. A prospective cohort study (2014-2019), including 22 fetuses with isolated ToF and 36 healthy controls, was conducted at BCNatal. Fetal 2D echocardiography was performed at third trimester and a cord blood sample was obtained at delivery to determine concentrations of Transforming growth factorβ (TGFβ) and angiogenic factors (placental growth factor, and soluble fms-like tyrosine kinase-1) were determined. Potential associations between echocardiographic parameters and cardiovascular biomarkers were evaluated. There were no significant differences between both groups in terms of maternal baseline characteristics except for a higher maternal body mass index in the ToF group and a higher rate of small for gestational age fetuses (31.8%) at ultrasound. More than half of the ToF cases required a Caesarean section (54.5%) and ToF neonates showed lower birthweight at a similar gestational age at birth. As expected ToF cases showed lower pulmonary valve z-scores with increased pulmonary peak systolic velocities. Aortic valve z-scores, aortic output and cardiac index were increased compared to controls. ToF-fetuses showed markedly increased cord blood TGFβ concentrations (24.9 ng/mL (15.6-45.3) vs. normal heart 15.7 ng/mL (7.2-24.3); p = 0.012) with no differences in angiogenic factors. TGFß levels showed a negative correlation with the pulmonary valve z-score (r=-0.697, p = 0.008) and positive correlation with aortic/pulmonary valve ratio (r = 0.611, p = 0.026). This study newly describes increased cord blood TGFβ concentrations in ToF compared to normal fetuses, which correlate with the severity of right ventricle outflow obstruction. These novel findings open a window of research opportunities on new prognostic and potential preventive strategies.