Prediction of transverse cerebellar diameter as a better indicator for estimation of gestational age in third trimester

Introduction: Prediction of gestational age (GA) based on sonographic fetal parameters is the cornerstone of modern obstetrics. In the third trimester all the individual parameter measurements become less accurate but recent studies have shown that fetal transcerebellar diameter is one such parameter that has remained consistently superior in prediction GA in both singleton and twin gestation. Aims and Objective: To predict gestational age using TCD & HC measurement in third trimester &correlated the prediction of gestational age by comparing transcerebellar diameter (TCD), Head circumference (HC) and LMP. Materials and Methods: Present study was done on 100 pregnant women in the Department of Radiodiagnosis, SIMS, Hapur from the month of October 2016 to March 2017. Study group included antenatal women between 28 to 40 weeks of gestation by applying simple random technique.Ultrasonography (USG) was done between 28 to 40 weeks of POG, after filling PNDT form. Result: Pearson’s correlation coefficient was 0.894 for TCD and 0.856 for HC. Although correlation was found to be statistically significant in both TCD and HC groups but GA had better correlation with TCD than the HC (p<0.001). Conclusion: The present study has revealed that TCD shows good correlation with the LMP for the prediction of gestational age in third trimester, however TCD has a better correlation with LMP than HC for the gestational age estimation.