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

Abstract

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 gestation
with clinically diagnosed fetal growth restriction, at the Tertiary care centre. Total 120 women were enrolled ,over
a period of 18 months ,from December 2020 to July 2022 .Biometry was performed using ultrasonography and
transcerebellar diameter and abdominal circumference ratio (TCD/AC) and head circumference and abdominal
circumference ratio (HC/AC) were calculated. All women were followed up till delivery and fetomaternal
outcome was recorded. After birth height, weight and ponderal index of the newborn were also noted. TCD/AC
ratio was correlated with birth weight and ponderal index, for predicting FGR. TCD/AC ratio was also compared
with 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 significant
negative correlation between TCD/AC ratio with birth weight and ponderal index, with a correlation coefficient
of 0.463 and 0.501 respectively. (p value < 0.001) TCD/AC was better predictor of fetal growth restriction with a
diagnostic accuracy of 84.17% versus 40.83% with HC/AC. Significant positive correlation was observed between
period 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 on
ultrasonography, with better diagnostic accuracy than routinely used HC/AC. Hence it should be performed for
all antenatal women clinically suspected to have FGR.