The Sonographic Evaluation of Gestational Age: A Comparative Study Utilizing Different Biometric Measurement Indices and Fetal Kidney Length

Abstract

Objective: Various indices have been introduced for estimating sonographic gestational age and have demonstrated varied diagnostic accuracy. The aim of this study was to evaluate the correlation of fetal kidney length (FKL) with some other traditional measurement parameters in determining an accurate gestational age. Materials and Methods: In this prospective study, healthy pregnant women, who had completed a scheduled and routine obstetrical sonogram, were included. During the sonogram, the measurement indices, biparietal diameter (BPD), abdominal circumference (AC), crown rump length (CRL), head circumference (HC), femur length (FL), and FKL were analyzed. The obstetrical measurements had been taken every 4 weeks from the 20th week of the pregnancy, until the end of the pregnancy (e.g., 20th, 24th, 28th, 32nd, 36th, 40th weeks). After data collection, the measurement data were analyzed with SPSS software. Results: There were significant ( P < .05) high strength of associations between FKL and the routine measurements of BPD ( r = 0.668), AC ( r = 0.770), CRL ( r = 0.792), HC ( r = 0.791), and FL ( r = 0.803). Conclusion: These results suggest possible significant positive relationships between FKL and BPD, AC, CRL, HC, and FL. It can be assumed that FKL might be a suitable index for determining gestational age especially in the late second and third trimester, when other measurement indices are less accurate.