Echocardiographic assessment of ventricular filling pressure during the second and third trimesters of gestation

Aims To confirm changes in the atrioventricular diastolic flow velocities (peak E, peak A, E/A ratio) with gestational age and to define whether these changes genuinely reflect variations in filling pressure in the fetal heart. Methods Fifty normal Pregnancies were studied between the 13th and the 37th weeks of gestation. The fetal flow velocity patterns were evaluated by pulsed-wave (PW) Doppler and the annular velocities of the atrioventricular valves by PW-Doppler tissue imaging (DTI). Results All indexes evaluated (atrioventricular peak flow and annular velocities) correlated significantly with gestational age. This correlation was stronger for the early diastolic indexes (tricuspid E and E-A, 0.69 and 0.78; mitral E and E-A, 0.62 and 0.77, respectively) and weaker for the end-diastolic indexes (tricuspid A and A(A), 0.46 and 0.37; mitral A and A(A), 0.45 and 0.39, respectively). Neither mitral nor tricuspid E/E-a ratio changed significantly with gestational age. Conclusions The lack of correlation between the Doppler-assessed ventricular filling pressures and gestational age suggests absence of significant changes of ventricular compliance during the second and third trimesters of pregnancy and a progressive enhancement of active relaxation and/or changes in loading conditions.