Determination of Gestational Age by Fetal Kidney Length Measurement in Uncomplicated Pregnancy in a Tertiary Care Centre

Introsution:  Gestational age of fetus is estimated by including various biometric parameters. Newer parameters like fetal kidney length have not been studied in Nepalese population. Objective: To determine gestational age by fetal kidney length measurement after the 20th week of gestation in healthy women with uncomplicated pregnancy. Method: Obstetric sonography was performed in 108 pregnant women with regular menstrual cycles, known menstrual age and uncomplicated pregnancy from 20 weeks to term. Fetal kidney length was evaluated as a measure to calculate the predicted gestational age. Results: The study showed mean fetal kidney length at 20-24, 25-29, 30-34 and 35-37 weeks gestation 22.5 ± 0.5, 26.9 ± 0.7, 32.32 ± 0.7 and 36.3 ± 0.6 mm, respectively. Overall, in second and third trimester, fetal kidney length showed strong linear correlation with gestation age with highest significant Pearson correlation coefficient of 0.989 as compared to other parameters (BPD=0.986, HC=0.976, AC= 0.971, FL= 0.984). Conclusion: Fetal kidney length can be used as a reliable parameter for determination of gestational age.