Color Doppler identification of a pericardial effusion in the fetus.

The aim of the study was to determine whether color Doppler identifies abnormal fluid within the pericardial space of the fetal were referred for heart. Second- and third-trimester fetuses diagnostic ultrasound. The four-chamber view of the fetal heart was imaged with real-time ultrasonography and examined for the presence or absence of separation of the pericardium from the epicardium, which extended from the atrioventricular junction toward the apex of the ventricle. To examine the pericardial space, the color Doppler maximal velocity was set at low Nyquist limits (0.08-0.24 m/s). In each fetus the transducer was angled so that the axis of the interventricular septum was parallel or tangential to the ultrasound beam to optimize the color Doppler recording. The control group consisted of 50 fetuses (16-38 weeks of gestation) who did not demonstrate evidence of pericardial effusion when examined with real-time ultrasound. Second- and third-trimester fetuses were selected from our database who demonstrated a pericardial effusion identified with real-time ultrasound. Color Doppler signals were not identified within the pericardial space in the 50 control fetuses. Fetuses with a pericardial effusion identified with real-time ultrasound demonstrated color Doppler within the pericardial space which was opposite to the direction of blood entering and exiting the ventricles. Color Doppler enhanced the detection of a pericardial effusion in the second-trimester fetus when the axis of the heart was and third-parallel or tangential to the ultrasound beam, which is suboptimal for real-time imaging. Color Doppler provides a new method to identify a pericardial effusion in the fetus during the second and third trimesters of pregnancy and complements the real-time examination.