Ultrasonographic Study of Fetal Parameters and Assessment of Gestational Age in North Indian Women

Introduction: Precise sonographic assessment of gestational age and fetal growth based on population specific references is essential for optimal obstetric management. This cross sectional study was conducted to establish ultrasound dating formulae in specified North Indian population. Methods: Fetal parameters in 583 singleton pregnant females were ultrasonographically measured for subsequent statistical analysis. Results: The means and standard deviations of biparietal diameter, head circumference, abdominal circumference and femur length for each gestational age (derived from LMP) were calculated. Cubic Regression Equations were derived for each fetal sonographic parameter and a population specific dating formula was prepared. Discussion: North Indian fetuses are smaller than European fetuses even before 3rd trimester and gestational ages derived from sonographic Western reference equations are underestimated in this population. Hence IUGR is diagnosed frequently, suggesting the need of population specific formulae and charts. This cross sectional study is an endeavor to establish population specific fetal biometric parameters for assessment of appropriate gestational age and fetal monitoring.