Ultrasonic assessment of gestational age by measurement of fetal kidney length in third trimester

Aim. Estimation of gestational age on basis of Last Menstrual period is reliable and universally followed. Ultrasound gives an objective evidence and dates pregnancy based on crown rump length, biparietal diameter, head circumference, abdominal circumference and femur length. Patients with uncertain dating in third trimester require a simple easy reproducible method when parameters are lagging behind and fetal kidney length can be used as an indicator for gestational age. Materials and methods. A total of 100 well dated normal pregnant patients were studied in third trimester using ultrasound and 3.5 mHz probe and purposive sampling technique. The fetal kidney size was measured and compared with other standard parameters used in pregnancy dating by Ultrasound. Statistical analysis was done using Karl Pearson coefficient and significance was found by student "t" test. Analysis was computed using statistical package SPSS version 11.5.P value is expressed in correlation coefficient. The third trimester was divided into two groups 28-34 weeks and 34-41 weeks. Results. The mean Kidney length was measured and was in the range of 28-38 mm in the first group A and 31-41 mm in second group B. Linear coefficient of individual parameters BPD, HC, AC, FL with gestational age showed strong correlation. Kidney length also showed strong correlation as compared to these parameters. Conclusion. Measurement of Kidney length is of value when other parameters do not accurately predict gestational age and is not affected by growth aberrations and artifacts associated with other standard parameters. What is new in this paper. This paper studies the possibility of using fetal kidney as a biometric indicator for fetal growth when BPD HC AC and FL are inconclusive due to any cause.