Correlation Between Fetal Transcerebellar Diameter And Gestational Age- Hospital Based Observational Study

Abstract

Objectives Primary Objective: To Find Correlation between the Transcerebellar Diameter with gestational age in the second and third trimester of the pregnancy. Secondary Objective: To evaluate the accuracy of TCD as against the conventional parameters of Biparietal diameter, Abdominal circumference, Femur length, Head circumference and composite of (BPD, AC, FL, HC) in Second and third trimester for predicting the gestational age. Design- A Cross-sectional study Subjects- 500 pregnant women between 26- 36weeks Main Outcome Measured- Transcerebellar diameter (TCD), Biparietal diameter (BPD), Abdominalcircumference (AC) and Femur length (FL) were measured. Data was analysed byKarl Pearson’s Coefficient, linear regression, multiple regression .Correlation between TCD and GA, GA and various other parameters like (BPD, HC, AC, FL) was computed by above described methods.This data was further used to formulate normogramsat 5th,50th, 90th percentiles. Results The mean gestational age of the pregnant women was 23.75±2.67yrs.55% were primigravida were as 45 % were multigravidas. There was statistical correlation between GA and all parameters but correlation between TCD and GA (r=0.961, p<0.001) was greater than the other parameters .The predictive value of TCD in our study was 98.5% with discrepancy of ±6days compared to actual GAin comparisonto FL (94.3% with discrepancy of ±12days compared to actual GA ), BPD (93.8% with discrepancy of ± 15days compared to actual GA), AC (93.2% with discrepancy of ±15days compared to actual GA),HC (91.2% with discrepancy of ±18days compared to actual GA). Conclusion Hence we can conclude that TCD is accurate, new alternative for predicting gestational age.It can be used as reliable parameter for estimating gestational age in second and third trimester of pregnancy especially women who are unaware of LMP or have a dating scan.