Role of transcerebellar diameter in fetal growth assessment and its correlation with conventional biometry-An institutional study

Background: Accurate assessment of gestational age (GA) for fetal development is of paramount importance in management of pregnancy and for favorable perinatal outcome.  The estimation of GA by fetal biometry using Biparietal Diameter (BPD), Head Circumference (HC), Abdominal Circumference (AC) and Femoral Length (FL) in estimation of gestational age (GA) is routinely followed. However, these parameters have limitations. BPD and HC are not reliable in third trimester; FL may be reduced in IUGR and skeletal malformations. Thus we evaluated the Transcerebellar diameter (TCD) as an alternate indicator for fetal growth and GA estimation. Aim: To validate the accuracy of TCD with fetal biometry and calculated ultrasound age (CUA) in assessment of fetal growth and GA in between 18 to 40 weeks of pregnancy. Materials and Methods: The prospective study was carried out with 200 pregnant women between 18 to 40 weeks referred to Radiology department ((JJM Medical College), for antenatal scanning. The subjects were divided into two groups (second and third trimesters). TCD was measured along with other routine parameter for growth assessment. Thus, calculated gestational age (GA) using TCD was compared with GA by Last menstrual period (LMP) and calculated ultrasound age (CUA). 