Prediction of Fetal Growth Restriction using Transcerebellar Diameter and Abdominal Circumference Ratio

Objective: To predict fetal growth restriction using transcerebellar diameter and abdominal circumference ratio(TCD/AC) in women with clinically diagnosed FGR.Materials and Methods: A prospective observational cohort study was conducted on women >28 weeks of gestationwith clinically diagnosed fetal growth restriction, at the Tertiary care centre. Total 120 women were enrolled ,overa period of 18 months ,from December 2020 to July 2022 .Biometry was performed using ultrasonography andtranscerebellar diameter and abdominal circumference ratio (TCD/AC) and head circumference and abdominalcircumference ratio (HC/AC) were calculated. All women were followed up till delivery and fetomaternaloutcome was recorded. After birth height, weight and ponderal index of the newborn were also noted. TCD/ACratio was correlated with birth weight and ponderal index, for predicting FGR. TCD/AC ratio was also comparedwith routinely used HC/AC ratio for predicting FGR.Statistical Analysis: The final analysis was done with the use of Statistical Package for Social Sciences (SPSS)software, IBM manufacturer, Chicago, USA, version 21.0®.Results: A cut off value of TCD/AC >0.14 was found to have a sensitivity, specificity, PPV and NPV of 87.36%,75.76%, 90.5% and 69.4% respectively with a diagnostic accuracy of 84.17%, in diagnosing FGR. There was a significantnegative correlation between TCD/AC ratio with birth weight and ponderal index, with a correlation coefficientof 0.463 and 0.501 respectively. (p value < 0.001) TCD/AC was better predictor of fetal growth restriction with adiagnostic accuracy of 84.17% versus 40.83% with HC/AC. Significant positive correlation was observed betweenperiod of gestation (weeks) with transcerebellar diameter (mm),with correlation coefficient of 0.497 (p<0.001).Conclusions: TCD/AC ratio is an effective gestational age independent parameter to predict FGR onultrasonography, with better diagnostic accuracy than routinely used HC/AC. Hence it should be performed forall antenatal women clinically suspected to have FGR.