VP15.07: Physiological changes in cardiac dimensions and function in low‐risk pregnancies

The aim of the study is to evaluate cardiac dimensions and function at different gestational age in a single centre low-risk pregnancies population. A cohort of 84 low-risk singleton pregnancies, without congenital anomalies, was collected prospectively in women undergoing routine prenatal assessment in our centre, between 15 and 37 weeks of gestation. Cardiac dimensions such as mitral valve (MV) and tricuspid valve (TV), left (LV) and right (RV) ventricle length and area were measured. Functional assessment was performed with tissue Doppler imaging (TDI) velocities, at the basal part of the right ventricular (RV) wall, at the interventricular septum (IVS) and at the left ventricular (LV) wall. Using this technique, a first positive wave (S' for systole), two negative waves (E' for diastole and A' for atrial systole) and their ratio (E/A ratio) were obtained. No significant changes were found for MV/TV ratio suggesting that LV and RV proportion remain stable during all pregnancy. Fetal cardiac dimensions significantly correlated with GA: MV and TV diameter; LV and RV length and area. LV E', RV E' and RV A' significantly increased; no significant increase was found for LV S', RV S', IVS S', or E/A ratio during pregnancy. RV E' significantly correlated to GA . There was no correlation between LV S', LV E' and LV A' and GA, nor between IVS S', IVS E' and IVS A' nor between RV S' and RV A'. We found a significant correlation between LV area and LV E', and between LV area and LV S'. No significant correlation was found between LV area and LV A'. We found a significant correlation between RV area and RV S', RV E' and RV A'. LV and RV dimensions and diastolic function increase during pregnancy, while LV and RV proportion and systolic function remain stable. Further studies are needed to determine if US investigation of fetal cardiac dimensions and function could be used as an additional tool to detect early signs of fetal cardiac disease and to stratify disease severity.