Reference resistance indices of the umbilical, fetal middle cerebral and uterine arteries at 24–42 weeks of gestation

Abstract

The objective of this cross-sectional study was to construct new reference ranges for Doppler flow velocity waveform resistance indices for the fetal umbilical artery, middle cerebral artery, placental and non-placental uterine arteries and the placentocerebral ratio in a large and minimally selected population attending a single clinic. Study design and data analysis adhered to a number of stringent and validated methodological recommendations derived both from the recent literature and from a review of earlier publications in this field. The final database comprised initial routine Doppler velocimetry at 24-42 weeks' gestation in 1675 pregnancies. Separate regression models were fitted to estimate the mean and standard deviation at each gestational age for each vessel. New charts, centile tables and regression equations are presented for the resistance indices of the fetal umbilical artery, middle cerebral artery, placental and non-placental uterine arteries and the mean of both uterine arteries and for the placentocerebral ratio.

Comparison of Diagnostic Efficacy of Umbilical Artery and Middle Cerebral Artery Waveform with Color Doppler Study for Detection of Intrauterine Growth Restriction

“…Kurmanavicius et al [2] in their study had mentioned a dynamic behavior of the MCA RI. They observed a parabolic pattern of change in the MCA RI with increasing age; this implies that a single cut-off value should not be employed for prediction of IUGR.…”

“…The cutoff value of the UA resistance index was taken as 0.72. This was according to the reference value of Kurmanavicius et al [2]. The value of UA RI [0.72 was taken as an indicator of IUGR and a value B0.72 was taken as normal; for the MCA, the cut-off value of MCA PI was taken as 1.5.…”

Fetal Doppler for prediction of adverse perinatal outcome in preeclampsia in a low resource setting

“…4 Similar to our findings, Ozeren et al also found that though cerebroumbilical PI ratio was higher in patients with preeclampsia, but had a lower sensitivity and diagnostic accuracy to predict adverse perinatal outcome. 11 Lakhar et al also found that umbilical artery PI is more sensitive than cerebroumbilical PI ratio in predicting adverse perinatal outcome. 14 …”

“…MCA-RI was considered abnormal if measurement was 2 SD below the mean. 11 All the ultrasound evaluations were done by a single obstetrician with expertise in Doppler sonography. The intrapartum management of the women and the mode of the delivery were as per the hospital protocol.…”

The value of colour doppler assessment of the uteroplacental circulation in predicting intrauterine growth restriction

“…16 They found that abnormal umbilical Doppler is associated with lower birth weight, lower APGAR score, and significant neonatal morbidity. Sensitivity of absent end diastolic flow was 100%.…”