Estimation of Fetal Age Based on Head Circumference and Femur Length in The Second Trimester: A Prospective Study

Abstract Accurate estimation of fetal age is crucial for prenatal care and management. This study aims to develop a model for estimating fetal age based on head circumference and femur length in the second trimester. A prospective study was conducted on 350 pregnant women between 14 and 27 weeks of gestation. Head circumference and femur length were measured using ultrasound, and fetal age was estimated using a combination of these parameters. Mean head circumference is found to be 179.51 cm with SD of 51.8. Mean femur length is found to be 34.05 cm with SD of 12.06. combined use of these two parameters showed correlation coefficient of 0.949. The model developed in this study can be used to estimate fetal age in the second trimester, which can help identify fetuses at risk of growth restriction and guide prenatal care.