OC26.04: Cardiac function between 11 and 35 weeks' gestation and nuchal translucency thickness in trisomy 21 fetuses

Abstract

Objectives: The increased nuchal translucency (NT) is a marker for trisomy 21 (Tri21) and for cardiac defects (CHDs), Cardiac dysfunction has been postulated in Tri21 fetuses. We aimed to study cardiac function throughout gestation in these fetuses. Methods: Echocardiography was performed on 49 trisomy 21 fetuses and 190 eukaryotic controls with normal hearts, (86 with a normal NT and 104 with a NT ≥95th percentile), between 11 and 35 weeks’ gestation. Measurements included: Eand Awave peak velocity, E/A velocity ratio and E/TVI ratio over the atrioventricular valves, myocardial performance index, semilunar valves peak velocity (PVel)and acceleration time (AT), stroke volume (SV) and cardiac output (C) and the ductus venosus pulsatility index for veins at 11–14 weeks’ gestation (DVPIV). Results: 11–13.9 weeks’ gestation: In Tri21 fetuses the semilunar valve PVels and tricuspid valve (TV) A-wave velocity were significantly reduced and TV E/A ratio and DVPIV significantly increased compared to normal NT controls. 14 and 21.9 weeks’ gestation: Aortic PVel, mitral (MV) and TV Eand A-wave velocities and MV E/TVI were significantly reduced in Tri21 fetuses without CHD compared to controls. 22 and 35 weeks’ gestation: In Tri21 fetuses with normal hearts the TV Eand A-wave velocity, right ventricular SV, aortic PVel and left ventricular CO were significantly reduced compared to normal NT controls. Conclusions: Tri21 fetuses have abnormal cardiac function irrespective of the NT thickness or presence of CHD. We found evidence for increased preload in early gestation with increased afterload thereafter along with biventricular systolic and diastolic dysfunction.