title: Efficacy of Transcerebellar Diameter/Abdominal Circumference Versus Head Circumference/Abdominal Circumference in Predicting Asymmetric Intrauterine Growth Retardation.
abstract: BACKGROUND
  The high incidence of IUGR and its low recognition lead to increasing perinatal morbidity and mortality for which prediction of IUGR with timely management decisions is of paramount importance. Many studies have compared the efficacy of several gestational age independent parameters and found that TCD/AC is a better predictor of asymmetric IUGR.
  
  
  OBJECTIVE
  To compare the accuracy of transcerebellar diameter/abdominal circumference with head circumference/abdominal circumference in predicting asymmetric intrauterine growth retardation after 20 weeks of gestation.
  
  
  METHODS
  The prospective study was conducted over a period of one year on 50 clinically suspected IUGR pregnancies who were evaluated with 3.5 MHz frequency ultrasound scanner by a single sonologist. BPD, HC, AC and FL along with TCD were measured for assessing the sonological gestational age. Two morphometric ratios- TCD/AC and HC/AC were calculated. Estimated fetal weight was calculated for all these pregnancies and its percentile was determined.
  
  
  METHODS
  The TCD/AC and HC/AC ratios were correlated with advancing gestational age to know if these were related to GA. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy (DA) for TCD/AC and HC/AC ratios in evaluating IUGR fetuses were calculated.
  
  
  RESULTS
  In the present study, linear relation of TCD and HC in IUGR fetuses with gestation was noted. The sensitivity, specificity, PPV, NPV & DA were 88%, 93.5%, 77.1%, 96.3% & 92.4% respectively for TCD/AC ratio versus 84%, 92%, 72.4%, 95.8% & 90.4% respectively for HC/AC ratio in predicting IUGR.
  
  
  CONCLUSIONS
  Both ratios were gestational age independent and can be used in detecting IUGR with good diagnostic accuracy. However, TCD/AC ratio had a better diagnostic validity and accuracy compared to HC/AC ratio in predicting asymmetric IUGR.
authors.affiliation: Senior Resident, Department of Radiodiagnosis, PK Das Institute of Medical Sciences , Palakkad, Kerala, India .
authors.lastname: Bhimarao
authors.affiliation: Assistant Professor, Department of Radiodiagnosis, PK Das Institute of Medical Sciences , Palakkad, Kerala, India .
authors.forename: Rashmi M
authors.initials: RM
authors.lastname: Nagaraju
authors.affiliation: Head, Department of Radiodiagnosis, Narayana Health, Mazumdar Shaw Multispecialty Hospital and Cancer Centre , Bangalore, Karnataka, India .
authors.forename: Venkataramana
authors.initials: V
authors.lastname: Bhat
authors.affiliation: Head, Department of Ultrasonography, Narayana Health, Mazumdar Shaw Multispecialty Hospital and Cancer Centre , Bangalore, Karnataka, India .
authors.forename: Puttanna Vn
authors.initials: PV
authors.lastname: Gowda
keywords: Fetal cerebellum; Gestational age; Growth restriction; Ultrasound