Fetal Kidney Length for Determining Gestational Age in Third Trimester

Abstract

Introduction: Accurate gestational age assessment is important in obstetric care. Ultrasonography plays a significant role in determination of Gestational Age. The ultrasonographic parameters used for GA determination are Crown rump Length, Biparietal diameter, Head circumference, and abdominal circumference and Femur length. Fetal kidney length (FKL) is one of the emerging parameter in estimation of gestational age. Renal length in mm is identified to approximate the gestational age in weeks. The present study is aimed to corroborate that FKL as a good parameter for gestational age estimation in third trimester. Objective: Is to ascertain the precision of the ultrasonographic 'foetal kidney length' measurement as a reliable parameter for determination of GA in third trimester. Material and Methods: One year Cross-Sectional and an Observational Study was conducted on 171 antenatal women in the third trimester after corroborating the gestational age by first trimester ultra sound and GA by LMP. Ultrasound measurements of Foetal kidney length were taken and correlation with last menstrual period gestational age and with other parameters (BPD, HC, AC, FL) were evaluated. Results: This study showed a good correlation of Mean kidney length with GA by LMP of (r=0.991) than the rest of the parameters, HC(r=0.836), FL(r=0.853), AC(r=0.853), BPD (r=0.734) with p value=0.000 for all the parameters. Conclusion: This study confirms that the fetal kidney length measurement is a reliable ultrasonographic parameter for estimating the gestational age accurately in the 3rd trimester and also it is observed that the correlation is increased when used along with other parameters.

Ultrasound Measurement of Foetal Kidney Length during Healthy Pregnancy: Relationship with Gestational Age

“…Our study revealed a linear increase in FKL with increasing GA. A unit change in mean kidney length corresponded to a 79% change in GA (ɼ 2 ). This correlation is in tandem with the reports of other authors ( 4 , 5 , 7 , 10 , 13 , 14 , 17 – 19 ). This finding supports the fact that FKL can be used for the estimation of GA.…”

Estimation of gestational age in third trimester using mean fetal kidney length in comparison with fetal biometry

“…Ugur et al [20] reported GA and FKL correlation (r =0.947) was lesser than GA and BPD (r= 0.975), GA and HC (r =0.974), GA and FL (r=0.967), but higher than GA and AC (r = 0.852). Gayam et al [5] observed that GA and FKL correlation was higher (r = 0.991) than GA and BPD (r = 0.734), GA and HC (r = 0.836), GA and AC (r = 0.853), GA and FL (r = 0.853). Ghaleb M.M et al [6] mentioned that correlation between GA and FKL was higher (r = 0.951) than GA and BPD (r = 0.753), GA and HC (r= 0.810), GA and AC (r = 0.828), GA and FL (r = 0.884).…”

“…Currently no single parameter is there to calculate the exact foetal gestational age during the third trimester, particularly after the 34 weeks. This is of particular concern to obstetricians who treat pregnant women who come late, have the wrong LMP, or uncertain of their LMP [5,6] . Except for urinary system anomalies such as obstructive uropathy in utero, foetal kidney is generally unaffected by foetal growth anomalies [7][8][9] .…”