Correlation between umbilical arterial doppler parameters and oligo-hydromnios in uncomplicated third trimester pregnancy


ABSTRACT: Background: Doppler study of the placental vessles has an important role in detection of impaired placental development and its complications. Amniotic fluid volume is an important parameter of placental function. Changes in umbilical artery doppler parameters in cases with decreasing amount of fluid volume in third pregnancy without cause may be due to placental malfunction. Objective: To evaluate the umbilical doppler parameters including Pulsatility Index (PI), Resistive Index (RI) and Systolic to Diastolic ratio (S/D) in full term pregnancies with normal amniotic fluid volume (amniotic fluid index of 8-25 cm),borderline amniotic fluid volume(5.1-8 cm) and those with oligohydramnios ( amniotic fluid volume less than 5 cm) to exclude placental malfunction in those with lower than normal fluid volume. Patients & Methods: One hundred seventeen full terms pregnant were evaluated between February 2014 and June 2016, at Azadi teaching hospital /Kirkuk city and outpatient clinic. Three groups were identified according to their amniotic fluid volume: decreased, borderline and normal amniotic fluid volume, the groups were labeled as (group A, B and C) respectively. Umbilical arterial doppler parameters (including RI, PI and S/D) were measured in all patients and the results were compared among the three groups. Results: There was no statistically significant difference (P=0.29) in the mean RI values among the groups, as the mean RI value was 0.61 for group A, 0.59 for group B and 0.59 for group C. The mean PI values of the three groups were not significantly different (P=0.75), neither the mean S/D values (P=0.77); mean PI value was 1.01 for group A, 0.98 for group B, and 0.97 for group C; S/D values were as the following 2.59 for group A, 2.51 for group B and 2.55 for group C. The same analysis was done in subgroups divided according to the maternal age, the older age group 34-40 years revealed significantly (P=0.049) higher mean S/D value in group C (0.50) compared to both group B (0.39) and group A (0.26); and significantly (P=0.05) higher mean RI value for group C (0.64) compared to group B (0.60) possibly due the smaller gestation age in group C. Conclusion: There is no correlation between umbilical artery velocity waveform parameters and amniotic fluid volume in uncomplicated third trimester pregnancy, so routine use of doppler in such cases is not recommended as there was no underlying placental dysfunction.