Pulmonary venous blood flow in the human fetus

Abstract

The objective of this study was to assess the feasibility of recording pulmonary venous blood flow in the human fetus, and to evaluate its relationship with gestational age. We studied 152 singleton pregnancies between the 19th and 40th weeks of gestation. One hundred and one cases were studied cross-sectionally to gather data on color flow visualization, and 51 were studied longitudinally. The upper right pulmonary vein was interrogated by pulsed wave Doppler to assess pulmonary venous blood flow. On color Doppler, the upper right pulmonary vein could be imaged in 89.6% of cases in the peri-atrial tract and in 75% of cases within the lung. The upper left pulmonary vein could only be imaged in 8% of cases close to the atrium and in 41% of cases within the lung. Reliable velocity waveforms were obtained in 91% of cases. The mean systolic peak velocity was 22.19 +/- 6.39 cm/s and the mean diastolic peak velocity was 22.1 +/- 6.35 cm/s. Both increased significantly with gestational age. Reversed end-diastolic blood flow was present in 18% of cases, regardless of gestational age and fetal heart rate. Expressed as a percentage of the forward flow velocity time integral, its value was 7.65 +/- 5.2%. Our data seem to confirm the presence of pulsatile pulmonary venous blood flow in the second- and third-trimester fetus. Normative data have been established for the second and third trimesters of pregnancy.

Predictive Value of Fetal Pulmonary Venous Flow Patterns in Identifying the Need for Atrial Septoplasty in the Newborn With Hypoplastic Left Ventricle

“…Our data demonstrate that PVD indices are both accurate and reproducible, with mean intraobserver and interobserver differences comparable to previous studies of PVD in both the fetus 30 and the adult. 31 However, there is modest variability in measurement of PVD indices, particularly with regard to the estimate of PVD A-wave magnitude, and therefore, PVD findings should be interpreted in the clinical setting with this foreknowledge.…”

“…Although in normal fetuses, PVD S-and D-wave velocities increase throughout gestation, and the S/D ratio and A-wave magnitude remain unchanged, 30 further work is needed to confirm the predictive capabilities of second-trimester PVD assessment in this population.…”

Fetal echo cardiography: the state of the art of the state of the heart

“…With the advent of color Doppler, tiny vessels became visible and thus reliably accessible to spectral Doppler evaluation. Reports emerged on pulmonary arterial and venous flow, on measurements across the fetal shunts such as the ductus arteriosus and foramen ovale, and even on the coronary artery and venous systems 37,[41][42][43][44][45][46][47][48][49][50] . The quantification of tricuspid valve insufficiency was shown to reveal valuable information on etiology and prognosis [51][52][53][54] .…”

Ebstein's anomaly with severe hypoplastic and stenotic pulmonary venous connections: an unusual cause of congenital chylothorax

“…Advances in molecular genetics and the use of invasive interventions, such as fetal skin biopsy, have enabled prenatal diagnosis 7 . Recent advances in threedimensional ultrasonography have enabled non-invasive prenatal diagnosis of congenital ichthyosis 8,9 .…”

“…We now believe that the primary cause of the congenital chylothorax was impairment of the systemic venous return, worsened by the obstructed and hypoplastic pulmonary venous system. Owing to reduced pulmonary blood flow in the fetus it is very difficult to visualize all four pulmonary veins 9 . Therefore, pulmonary venous hypoplasia is not amenable to prenatal diagnosis.…”