WS06: Fetal echocardiography WS06‐01Human fetal cardiac function during the first trimester of pregnancy

Abstract

IntroductionThe hypothesis was tested whether the improvement in the human fetal cardiac diastolic and systolic functions are associated with changes in the cardiac volume blood flow, inflow blood velocity waveform characteristics, systemic venous blood flow parameters, umbilical artery velocimetry and fetal nuchal translucency. By a longitudinal study protocol the inflow and outflow blood velocity waveforms were obtained in 16 uncomplicated pregnancies at 6, 7, 8, 9 and 10 weeks.ResultsThe proportion of isovolumetric relaxation time decreased and the proportions of filling and ejection times of the cardiac cycle increased significantly from 6 to 7 weeks. The proportion of isovolumetric contraction decreased between 8 and 9 weeks. Every inflow waveform was monophasic before 9 weeks but it was biphasic in all cases at 10 weeks. Mean velocity of inflow and outflow increased between 6 and 7 weeks and Vmean of inflow increased further after 8 weeks. At 9 and 10 weeks, atrioventriculu valve recurgitation (AVVR) was present in 4 and 7 fetuses, respectively. Nuchal translucency was greater in fetuses with AVVR present at 10 weeks compared with non‐AVVR cases.ConclusionImprovement in the diastolic function of fetal heart between 6 and 7 weeks is accompanied by simultaneous increase in the mean velocities across inflow and outflow tracts. Appearance of biphasic inflow pattern is associated with significant change in systolic function between 8 and 9 weeks. AVVR is a common finding at 10 weeks of gestation.