Role of Doppler Velocimetry and Placental Thickness in Evaluation of IUGR

Objectives: The present study was to evaluate the role of Doppler velocimetry of umbilical artery and middle cerebral artery for non-anomalous fetus with suspected IUGR. And to evaluate the placental thickness in suspected cases of IUGR. Methods: A detailed clinical history, fetal biometry, amniotic fluid assessment and color Doppler study were performed on S10 voluson with a curvilinear transducer, having a variable frequency of 1.0-5.0 MHz. The ratio between the pulsatility index (PI) of the middle cerebral artery (MCA) and the umbilical artery (UA) PI, known as the MCA/Umb A PI ratio or Cerebral-umbilical ratio, was calculated. In our study, a single cutoff value of 1.0[21] for the MCA/Umb A PI ratio was utilized. Velocimetry was deemed normal if the ratio was above this threshold and abnormal if it fell below it. Placental thickness was assessed at the level of umbilical cord insertion, with the maximum thickness recorded in cross-section. Results: In umbilical artery, PI and RI of IUGR fetuses were significantly higher than that of normal fetuses (1.508±0.581 vs 1.053±0.233; p=0.001, 0.857±0.238 vs 0.668±0.125; p=0.001). In middle cerebral artery PI and RI of middle cerebral artery was significantly lower than that of normal fetuses (1.206±0.380 vs 1.607±0.319; p<0.001, 0.597±0.122 vs 0.704±0.138; p=0.002). Cerebro-placental ratio(CPR) of IUGR fetuses were significantly lower than that of normal fetuses (0.848±0.335 vs 1.609±0.526; p<0.001). Among the total of 70 patients assessed, 50 fetuses were diagnosed with intrauterine growth restriction (IUGR), while 20 did not exhibit IUGR. Within the group of 50 fetuses with IUGR, 34 were classified as having asymmetric IUGR, and the remaining 16 fetuses were categorized as having symmetric IUGR. Conclusions: Cerebro-Placental Ratio (CPR) is the superior predictor of IUGR in comparison to PI or RI values of MCA or UA. The PI of the umbilical artery has higher diagnostic accuracy as compared to the RI of umbilical artery and PI and RI of middle cerebral artery. Since PI and RI of MCA has least diagnostic accuracy in predicting IUGR, it is recommended to be used along with other Doppler indices in the setting of suspected IUGR.