Correlation of Gestational Age with Fetal Renal Length in Third Trimester Pregnancy

Abstract

Objectives: The objective of the study was to establish normative fetal kidney length (FKL) ranges in third- trimester pregnancy and comparing its accuracy with conventionally used biometric parameters. Introduction: FKL was compared with conventional parameters such as biparietal diameter, head circumference, abdominal circumference (AC), and femur length using Pearson’s correlation coefficient in third-trimester pregnancy as an adjunct in the determination of gestational age (GA). Materials and Methods: The study was conducted on 152 singleton uncomplicated pregnancies in their third trimester (28–40 weeks) who were sure of their last menstrual period. After measurement of conventional parameters, FKL was measured, and correlation was obtained with GA and its efficacy was compared with other parameters. Results: FKL showed a Pearson’s correlation coefficient of 0.907 and a determination coefficient of 0.822 with GA. The test was significant at P < 0.05. It was followed by AC with a correlation coefficient of 0.901. Conclusion: FKL showed a strong correlation with GA compared to other conventional parameters and can easily be included in routine obstetric scan to enhance the accuracy of GA measurement and in cases where conventional parameters are difficult to obtain, especially in third trimester due to head engagement, asynclitism, and in breech presentation.

Keywords

• abdominal circumference
• biparietal diameter
• femur length
• fetal kidney length
• gestational age
• head circumference.