BLOOD FLOW VELOCITY PARAMETERS IN THE DUCTUS VENOSUS IN FETUSES WITH CONGENITAL HEART DEFECTS

Objective: To investigate absolute flow velocity parameters in the ductus venosus of fetuses with congenital heart defects (CHD). Materials and methods: In this cross-sectional study, we assessed the velocities of a-waves, S-waves, D-waves, and time-averaged maximum velocity (TAMX) in the ductus venosus of 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. Results: 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). Conclusion: 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. © A group of authors, 2025.