Doppler velocimetry of fetal pericardial fluid

ObjectiveTo investigate the flow of normal fetal pericardial fluid (PF) with increasing gestational age using Doppler velocimetry.MethodNinety-five fetuses between 18 and 37 weeks of gestation with PF within the normal range were studied. PF was measured in 4-chamber view using M-mode or real-time ultrasound. Color Doppler was used to display and guide the pulse wave assessment of PF flow. PF waveforms as well as systolic and diastolic velocities were recorded and correlated with gestational age.ResultsPF was detected in all of the fetuses. The mean thickness of the PF rim was 0.95 ± 0.45 mm. PF flowed toward the cardiac apex during systole and toward the atrium during diastole. PF waveforms showed bidirectional flow in all fetuses. The flow velocity PF was positively correlated with gestational age in both systole and diastole.ConclusionFlow velocity of fetal PF increases linearly in both systole and diastole with gestational age. This might indirectly indicate a maturational change in myocardial performance as myocardial velocity is increased.