Accuracy of fetal kidney length and transcerebellar diameter in assessment of gestational age in normal and growth restricted fetuses

Background: Accurate monitoring of fetal gestational age is one of the most critical components of prenatal care. Aim: This study intends to determine the accuracy of fetal gestational age estimation using mean fetal kidney length and transcerebellar diameter and comparing their efficacy with other biometric measurements in normal and growth restricted fetuses. Subjects and Methods: Our prospective study was conducted on 251 pregnant women seeking for routine ultrasound examination during the second half of pregnancy at Al-Hussein and Al-Zaharaa university hospitals starting from November 2021 till November 2022 and the following fetal biometric parameters were measured transabdominally during each ultrasound examination including the transcerebellar diameter (TCD), fetal kidney length (FKL), biparietal diameter (BPD), head circumferences (HC), abdominal circumferences (AC) and femur length (FL). Results: The FKL and TCD in the present study correlated well with the assigned GA. The relationship of fetal kidney growth and TCD with GA is statistically significant. The present study hence validates the recommendation that FKL and TCD can be used as an important sonographic parameter for accurate prediction of fetal gestation age especially in IUGR fetuses. Conclusion: Fetal kidney length and TCD are accurate parameters for assessment of gestational age in 2nd half of normal pregnancy. In addition, fetal kidney length and TCD are highly accurate for detection of gestation age in IUGR suspected pregnancies.