Investigating Uterine Artery Doppler Indices in Normal Pregnancies

Background & Objective: Clinical use of uterine artery (UtA) Doppler ultrasound imaging requires reference values, however despite the common use of UtA Doppler examination during pregnancy, to the best of our knowledge, there is no such range for Iranian pregnant women. Therefore, the present study was conducted aimed to investigate uterine artery Doppler indices in Iranian normal pregnancies. Materials & Methods: This observational longitudinal study was conducted on 486 low-risk pregnant women. The amount of plausibility index (PI) and resistance index (RI), as well as the presence of diastolic notch was assessed in weeks 11 to 14, 17 to 24, and 27 to 32 through Doppler ultrasound. Results: The bilateral notch for gestational age of 11 to 14 weeks was detected at about 6%, for gestational age of 17 to 24 weeks was 4.2% and for gestational age of 27 to 32 weeks was 3.6%. Reference intervals for mean uterine artery PI according to gestational ages showed a significant difference between different percentages (p<0.001). Also, there is a significant relationship between the mean uterine arteries PI/RI and the presence or absence of pregnancy complications (IUGR, premature birth, IUFD) among the participants. Conclusion: The results of this research showed a significant relationship between PI and pregnancy complications, while this was not detected in RI and diastolic notch. These results are relatively consistent with the findings of researchers in other countries.