P46.10: Changes in the ductus venosus in fetuses with growth restriction

To demonstrate differences in the diameter and pulsatility index (PI) of the ductus venosus (DV) and in the cerebroplacental ratio (CPR) in fetuses with intrauterine growth restriction (IUGR). This was a cross-sectional cohort study at Thammasat University Hospital. At least three measurements were made in each fetus during fetal quiescence. The fetuses with IUGR were classified as a study group. Controls were matched by gestational age (GA). Abnormal DV diameter or PI was defined as greater than the 95 percentile for GA. Abnormal CPR defined as less than 1.08. All fetuses were compared with GA matched normal fetal Doppler studies. Thirty-three fetuses with IUGR were compared against 33 normal fetuses. There was significantly more abnormal DV diameter in the study group (P = 0.01). Of study group, 6/33 had abnormal DV diameter, while three of 33 had abnormal DV PI. There were 2/33 cases of abnormal CPR; all had both abnormal DV size and DV PI. The tissue of the DV is likely sensitive to fetal cerebral oxygen content. Relative cerebral hypoxia in fetuses with IUGR results in a dilation of the DV which then increases the blood flow through the DV toward the fetal heart and head. These changes in the DV occur before abnormal CPR.