Ductus venosus flow velocity waveforms in relation to fetal behavioural states

Abstract

Objectives To establish the reproducibility of flow velocity waveforms in the human ductus venosus and to assess the influence of fetal behavioural states on these waveforms in normal term fetuses. Design Reproducibility of Doppler waveform recording and analysis was studied in 10 normal pregnancies. The relation between ductus venosus flow velocities and behavioural states was investigated in 19 other term fetuses. Time‐averaged, peak systolic, peak diastolic velocity, peak systolic/diastolic ratio and period time were calculated in both cross sectional studies. Setting Outpatient clinic, department of obstetrics (prenatal diagnosis section), Academic Hospital, Rotterdam—Dijkzigt. Subject Twenty‐nine women with normal singleton pregnancies at 36 to 39 weeks of gestation, resulting in uncomplicated births of healthy infants. Results Within‐patient coefficients of variation, ductus venosus waveform recordings were approximately 8 to 10% except for the peak systolic/diastolic ratio (4.3%). A decrease of approximately 30% was established for peak systolic, peak diastolic velocity and time‐averaged velocity during behavioural state 1F (quiet sleep) as compared with state 2F (active sleep). Conclusions Flow velocity waveform recording in the ductus venosus demonstrates acceptable reproducibility. Fetal behavioural state‐dependent changes were observed, suggesting a redistribution of umbilical venous blood through the ductus venosus shunt during the quiet sleep state.

Umbilical venous volume flow and fetal behavioral states in the normally developing fetus

“…This is further supported by a shift from right to left ventricular cardiac output 20 as well as a 7.4% rise in FHR observed in the present study suggesting elevated left ventricular cardiac output during fetal behavioral state 2F. Increased cardiac output should be balanced by a raised cardiac inflow and this is suggested by elevated ductus venosus flow velocities reported previously 6 and the slightly increased (9.7%) UV volume flow during fetal behavioral state 2F. A significant increase in UV cross-sectional vessel area of 5.6% was found during behavioral state 2F.…”

“…Flow velocity waveform changes in the fetal descending aorta 4 and internal carotid artery 5 suggest increased left ventricular output of well-oxygenated blood flow with the purpose of meeting raised energy demands during the active sleep state. This was supported by increased time-averaged flow velocities in the ductus venosus 6 and at the level of the forame ovale 7 , suggesting elevated venous inflow during this behavioral state. The question arises as to whether the state dependency of venous inflow also exists at the level of the umbilical vein.…”

Intrauterine Growth Retardation and Fetal Cardiac Function

“…Moreover, the behavioral states of the fetus influence the intracardiac hemodynamics and consequently those of the venous compartment. Therefore the recordings should only be performed during phases of breath holding and fetal quietness [22,23]. It is particularly important to create correct scanning planes where the Doppler observations are performed.…”

Cerebral Hemodynamics and Fetal Behavioral States in IUGR Fetuses

“…4 Other studies have shown that some vascular fetal districts are affected, in their velocimetric patterns, also by "physiologic" conditions. [5][6][7][8][14][15][16][17][18] It is well known that correct evaluation and interpretation of Doppler hemodynamic patterns depends not only on appropriate technical skills but also on the knowledge of the physical and physiological variables that can influence fetal velocity waveform profile.…”