Maximal velocity of fetal pulmonary venous blood flow

Abstract

Introduction: Doppler imaging of foetal pulmonary veins plays a crucial role in prenatal cardiology centres. Therefore, we established reference ranges for maximal fetal pulmonary venous blood flow velocity for our unit. Material and methods: A database of fetal ultrasound and echocardiographic examinations was analysed retrospectively. Healthy fetuses with no evidence of heart defect or any abnormality at the time of examination were selected as a study group. Fetuses with functional or morphological anomalies were excluded. The obtained data included: gestational age of pregnancy according to last menstrual period, maximal velocity of blood flow through pulmonary veins (V max for PVs), prenatal cardiological diagnosis, extracardiac anomalies, and extracardiac abnormalities. Results: Ultrasound data were collected at 18-39 weeks of gestation in singleton pregnancies. The study group contained 184 healthy fetuses. Scatter graph and reference ranges for their V max for PVs during pregnancy were prepared. The regression equation for V max for PVs as a function of gestational age (GA) in days was: V max for PVs (cm/sec) = 0.1 x GA (in days) + 5.5 (r = 0.45, CI 0.95). Conclusion: We presented normal ranges for pulmonary vein Doppler flow for the 18 th-38 th week of gestation in fetuses with normal heart anatomy, showing a steady increase towards the term in statistical analysis. However, each case should be approached individually because interpretation of the calculated values might not be very easy or straightforward.

Fetal foramen ovale flap tracings, as determined by M-mode echocardiography between weeks 24 and 39 of gestation

“…Pulmonary vein blood flow velocity at the level of their connection to the left atrium plays a role in shape and movement of FO, in normal and abnormal conditions [12]. In normal fetuses with advancing gestational age, there is an increase in pulmonary blood flow [13], so one might expect a decrease in the FO index, as it should be closed postnatally [14]. On the other hand, it may suggest that despite an increased pulmonary blood flow in fetal lungs, there is still preserved functional stability at the atrial level.…”

Prenatal ultrasound assessment of fetal lung development in normal and complicated by fetal and maternal diseases pregnancy

“…That is why many scientists try to rule out noninvasive methods to reach the same or even better predicting results. For this purpose, fetal echocardiography as widely available tools is used in normal and complicated by fetal and maternal diseases pregnancy to assess proper fetal lung development 2–14 …”

“…Of them maternal inflammation plays a role, regardless of its etiology: bacterial or viral infection, autoimmune disease, severe hypoxia and injury. Physiologically with gestation resistance decrease in fetal pulmonary vasculature 7 . Impaired vascular and pulmonary tissue growth disenable blood pressure to decrease, what could be mirrored by shorter pulmonary artery AT in echocardiographic examination.…”

“…For this purpose, fetal echocardiography as widely available tools is used in normal and complicated by fetal and maternal diseases pregnancy to assess proper fetal lung development. [2][3][4][5][6][7][8][9][10][11][12][13][14] Fetal respiratory system is directly influenced by the fetal cardiovascular system and the other way around. The left ventricle is predominantly dedicated to the coronary circulation and upper body, while the right ventricle is the main distributor to the lower part of the body, the placenta and the lungs.…”

Dextro-transposition of great vessels: difficult to detect prenatally, one of the most dangerous and one of the best prognosed

“…Most studies have concluded that the assessment of the atrial septum is useful (29,31). Pulmonary flow is growing during the pregnancy which may cause the restriction of the FO (32,33). Therefore, the assessment of the FO in the twentieth weeks of pregnancy could be insufficient to accurately predict the newborns' condition after delivery (22,33).…”