Doppler Ultrasound Assessment of Portal Venous Flow Changes During Pregnancy

Background & Objectives: We aimed to evaluate portal venous flow changes during pregnancy by evaluating flow velocities and patterns in relation to gestational age. Methods: A total of 130 pregnant comprised (age, 18–45 years [mean, 29.3± 5.31 years]) were recruited. The subjects were divided into: Group 1: thirty four subjects in the 1sttrimester; Group 2: fifty five subjects in the 2nd trimester; and Group 3: forty one subjects in the 3rd trimesters. Portal vein diameter and maximum and minimum velocities were measured from the main portal vein. Spectral analysis was performed by calculating the portal vein pulsatility: minimum portal vein velocity divided by its maximum velocity. Results: The (mean±SD) maximum flow velocities (cm/sec) were higher in group 2 (31.58± 10.33) than those in groups 1 (29.44± 8.97) and 3: (26.8± 6.78), with a significant difference between groups 2 and 3. The mean minimum flow velocities were again higher in group 2: (20.89 ± 5.99) than those in groups 1 (17.71± 5.67) and 3 (18.2± 4.9) with a significant difference between groups 1 and 2. There were no statistically significant differences in mean portal vein diameter among the groups. The portal vein pulsatility value progressively increased with increasing gestational age from 0.60 in the first trimester to 0.68 in the third trimester, with statistical significant differences between groups 1 and 2 and groups 1 and 3. Conclusion: There is a significant increase in maximum portal vein flow velocity during the second trimester, with decreased waveform pulsatility with advancing gestational age.