Correlation between the Doppler velocimetry findings of the uterine arteries during the first and second trimesters of pregnancy

Abstract

SUMMARY OBJECTIVES.Evaluate the feasibility of transvaginal uterine artery Doppler examination in the first and second trimesters of pregnancy, establish reference ranges in a Brazilian population and examine the correlation between these Doppler findings. METHODS. Longitudinal prospective study at the antenatal clinic of a tertiary teaching hospital. Uterine artery Doppler examinations were carried out transvaginally at 11 to 14 weeks and 20 to 25 weeks of gestation. Uterine artery mean pulsatility index (PI) distributions were determined and the presence or absence of an early diastolic notch was also noted. The degree of correlation between first and second trimester Doppler findings was examined. RESULTS. Three hundred and forty four women with live singleton pregnancies and normal outcome were first examined at a mean gestation of 12.7 weeks. The values corresponding to the 50th and 95th centiles of mean PI were 1.69 and 2.48. Bilateral notches were observed in 44% of cases and unilateral notches were present in 19%. Second trimester Doppler examinations were carried out at a mean gestation of 23.2 weeks and corresponding figures for the 50th and 95th centiles were 1.03 and 1.57. Bilateral notches were noted in 4.4% of the cases. First trimester impedance indices were significantly higher and positively correlated to second trimester findings (r = 0.42, p<0.0001). CONCLUSION. Uterine artery Doppler examination can be successfully performed transvaginally and incorporated into scans that are routinely offered to women during their antenatal care in the first and second trimesters. Doppler indices obtained during the first trimester are significantly higher than those of the second trimester and findings at both scans are significantly correlated.

Reference range of uterine artery Doppler parameters between the 11th and 14th pregnancy weeks in a population sample from Northeast Brazil

“…This mean UtA-PI value was similar to values obtained for the unaffected group in other studies that utilised transabdominal uterine artery Doppler [21][22][23][24][25] . However, our observed mean UtA-PI value was lower than the mean UtA-PI value of 1.6 reported by another study conducted in Brazil that utilised transvaginal uterine artery Doppler to examine 344 pregnancies with normal pregnancy outcomes 26 .…”

Reproducibility of first‐ and second‐trimester uterine artery pulsatility index measured by transvaginal and transabdominal ultrasound

“…Regarding the difference in angle of insonation, we believe that the standard position/direction of the uterine artery facilitates a better angle to be obtained by TVS. In a prospective longitudinal study, Doppler of the uterine arteries, using a transvaginal approach, at 11–14 and 20–25 weeks of gestation in 344 normal singleton pregnancies, showed easy identification of the uterine arteries at the level of the internal cervical os; moreover, TVS gave clear waveforms owing to the close proximity of the transducer to the uterine vessel.…”

Comparison of two different sites of measurement for transabdominal uterine artery Doppler velocimetry at 11–13 weeks

“…However, this approach seems to be difficult to apply to first‐trimester examination. Liao et al also found that measurement at Site B is not applicable to the first trimester and that different techniques should be employed22. First, the uterus is much smaller during the first trimester and sometimes there is no apparent crossover with the external iliac artery to allow appropriate measurement.…”