Fetal kidney length as a parameter for determination of gestational age in pregnancy

Nirmala Shivalingaiah, Sowmya K, Ananya R, Kanmani TR, Marimuthu P


Background: Establishing the gestational age of the fetus, especially in late trimester is a challenge to aptly treat the pregnant woman. Ultrasound parameters like BPD, HC, AC & FL in second and third trimesters are not very reliable for dating the pregnancy. Fetal kidney length has been studied and shown to strongly correlate with the gestational age in late trimesters even in IUGR fetuses.

Methods: The present study evaluated the role of kidney length in determining the gestation age with the study population of 60 pregnant women between 24 - 36 weeks of gestation whose pregnancies were dated accurately by early dating scan. Length of the nearer kidney was measured in centimeters, 4 weekly in the longitudinal axis along with other biometric indices.

Results: According to the observations, the mean deviation from the gestational age at all the weeks is least for KL. The result indicates that the kidney length in the present study correlated well with the assigned gestational age and found almost same as all the ultrasound biometric parameters put together.  

Conclusions: Kidney length can be used as an individual parameter in estimating gestational age, especially in later trimesters, where biometric indices may not be much reliable.


Pregnancy, Kidney length, Ultrasound, Gestational age

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