Blood flow velocity parameters in the ductus venosus in fetuses with congenital heart defects
07.11.2025
15:42
The authors present the first Russian study on blood flow velocity characteristics in the ductus venosus of fetuses with congenital heart defects (CHD), focusing on observations devoid of combined placental or fetal pathologies that could potentially influence the intracardiac hemodynamics.
In this cross-sectional study the velocities of a-waves, S-waves, D-waves, and time-averaged maximum velocity (TAMX) in the ductus venosus were evaluated in a total cohort of 171 fetuses with CHD, including 47 fetuses with right heart defects (subgroup 1) and 124 fetuses with other forms of defects (subgroup 2). A comparative analysis of the obtained indicators was conducted across three gestational intervals: 18–21 weeks (x1), 22–29 weeks (x2), and 30–40 weeks (x3) of pregnancy.
The a-wave velocity below the 5th percentile was observed in 18.1%, 21.3%, and 16.9% of cases in the overall cohort and in subgroups 1 and 2, respectively. In the overall group and subgroup 2, there was a significant increase in the a-wave, S-wave, D-wave, and TAMX velocities in each subsequent gestational interval (p<0.001), consistent with the findings in the healthy population. In subgroup 1, there were no significant changes in a-wave velocity between gestational intervals (p>0.05), whereas increases in S-wave, D-wave, and TAMX values were recorded only between the first and third gestational intervals (x1–x3) (p=0.001). No differences were observed between the gestational intervals x1–x2 and x2–x3 (p>0.05). Comparative analysis of a-wave, S-wave, and D-wave velocities and TAMC did not reveal statistically significant differences between the study subgroups (p>0.05).
A decrease in the velocity of oxygenated blood flow to the fetal heart during the atrial contraction phase (a-wave) was observed in 16–21% of fetuses with cardiac pathology, indicating an increased risk of hypoxic complications. The lack of a physiological increase in flow velocities in the ductus venosus among fetuses with right heart defects underscores the need for additional antenatal monitoring in these patients.
