Transverse Cerebellar Diameter - A Marker for Estimation of Gestational Age

The cerebellum lies in the posterior cranial fossa. In the embryo, cerebellum appears at the end of fifth week. The cerebellum is easily visualized sonographically. Measurement and demonstration of fetal cerebellum is a new and unique parameter of fetal brain growth and also useful in assessing gestational age. The prospective study was carried out on 50 antenatal patients (20-40 years of age) between 14-40 weeks of pregnancy attending the clinic for routine ultrasound examination. Ultrosonographic measurement of Transverse cerebellar diameter (TCD) was done to assess the Gestational age. Mean TCD was 17.32 mm in 14-20 weeks of gestation, 26.63 mm in 21-30 weeks and 40.73mm in 31-40 weeks. Regression analysis indicates a significant relationship between TCD and gestational age, indicating that TCD is a good marker for estimation of gestional age.