Comparison of transcerebellar diameter with conventional fetal biometric parameters like biparietal diameter, head circumference, femur length and abdominal circumference in predicting gestational age in third trimester

Background: Gestational age estimation in third trimester is very crucial to impart holistic antenatal care and a pre-requisite plan various interventions. Transcerebellar diameter can predict gestational reliably as it grows progressively with gestation not affected by fetal lie, skull shape growth disorders. This study was performed compare TCD conventional parameters like BPD, HC, FL AC accurate prediction of age.Methods: Fetal biometry on 140 women singleton pregnancy abdominal ultrasound. Women included were sure their LMP, had dating scan anomalies ruled out. Analysis done using Pearsons coefficient (r) regression, p<0.05 considered statistically significant.Results: GA LMP showed maximum correlation (r=0.920 p<0.001) followed HC (r=0.871) (r=0.833). Least seen BPD (r=0.789). On comparing parameters, correlated maximally (r=0.882) (r=0.868) (r=0.853) least (r=0.793).Conclusions: serve reliable parameter for evaluation whose unknown or when they present late without having because strong significant TCD. Moreover, also provide cases restriction, macrosomia, skeletal dysplasia where AC, becomes unreliable. Therefore, should be routine biometry.