Accuracy of Trans cerebellar Diameter in Comparison to Fetal Biometric Parameters for Gestational Age Estimation in Second and Third Trimester

Background: A crucial part of managing pregnancy and assessing fetal growth and development in obstetrics is precisely calculating the gestational age (GA). The fetal cerebellum can be observed through USG as early as 10-11 weeks of pregnancy. Since changes in growth have little effect on the cerebellum's development, the TCD should be more accurate indicator for predicting GA.Aim: This study that aimed to evaluate the accuracy of TCD in estimation of gestational age in singleton gestation as an accurate parameter and to compare it with other routine parameters (BPD, AC and FL) in normal pregnant women.Patients and methods: This analytic cross-sectional study that was conducted on 100 pregnant women in their second and third trimester at the Obstetrics and Gynecology clinic of Suez Canal University Hospitals in the period from October 2021 to June 2022. The whole patients were fulfilling the inclusion and exclusion criteria and counseled for the study and then thorough history taking, clinical examination were performed followed by ultrasound examination and measurements of the Trans cerebellar diameter, Biparietal diameter, Abdominal circumference and femur length were recorded.Results: Our findings revealed a good degree of dependability, with the GA estimated by TCD and GA computed by LMP showing a high degree of agreement. The least trustworthy measure was abdominal circumference, followed by FL and BPD. Regression analysis revealed that the TCD and the LMP had the strongest correlation, while the BPD had the weakest; nonetheless, all parameters were significant predictors of the GA