Correlation between Fetal Kidney Length and Fetal Biometry for Gestational Age Determination in Third Trimester in Low-risk Pregnancy

Abstract

Estimation of gestational age plays an important role in quality maternity care. Ultrasound provides an accurate method of determining fetal age in utero. A prospective study was done in 150 pregnant women with low-risk pregnancy after 28 weeks of gestation who were sure of their last menstrual period or had underwent dating scan. The aim of this study was to determine the accuracy and application of fetal kidney length (FKL) measurement in determining the gestational age of the fetus in the third trimester and compare its accuracy with that of other fetal biometric indices [biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL)]. The FKL measurements showed that there is a linear relationship between FKL and gestational age. The mean kidney length in mm approximates the gestational age in third trimester as predicted by BPD, HC, AC, and FL. The FKL dates the pregnancy more accurately (correlation coefficient 0.98) when compared with BPD, HC, AC, and FL. The results obtained concluded that FKL can be used as a reliable parameter for determination of gestational age.