Takano M, et al. – The objectives of this study are to evaluate the utility of the Dual gate Doppler (DD) method for measurement of fetal E/e', and to ascertain reference ranges for normal fetuses. Bilateral E/e' of normal fetuses, measured utilizing the DD method, reduced with gestational age (GA), which is considered identified with myocardial maturity. The DD method is useful and convenient for assessing fetal E/e’ to estimate diastolic function in the prenatal period.