A COMPARATIVE STUDY OF RENAL SIZE IN NEWBORN BABIES

Background: In neonatal period usual presentation of renal anomalies is an increase or decrease in renal size. This study was conducted to assess renal size of normal newborn babies and to determine the best parameter against which kidney size should be associated and whether it is similar for small for gestational age and appropriate for gestational age babies. Material and Methods: This was a hospital-based case-control study, conducted over six months at Jinnah Postgraduate Medical Center and National Institute of Child Health, Karachi. One hundred and twenty-eight newborn babies were included. Kidney length and depth were measured by ultrasound. Birth weight, body length and head circumference of babies were measured. Gestational age was assessed using Dubowitz method. Kidney size was compared to birth weight, length, head circumference and gestational age. Results: Out of 128 children 59% were boys and 41% girls. Seventy-one (55.4%) were small for gestational age and 57 (44.6%) appropriate for gestational age. Birth weights of babies ranged from 1100-4200 grams, lengths 39-53 cm and head circumference 30-37 cm. There was a positive correlation of kidney size with birth weight, body length and gestational age, strongest in case of birth weight. Appropriate for gestational age babies had larger kidneys than small for gestational age babies. Conclusion: There is a strong correlation between kidney size and birth weight of newborn babies. Small for gestational age babies have significantly smaller kidneys as compared to appropriate for gestational age babies.