Reference ranges for sonographic renal dimensions in preterm infants.

BACKGROUND

Ultrasonographic measurement of kidney dimensions is important in evaluation of renal disease in preterm infants who have multiple comorbidities that affect renal function.

OBJECTIVE

The purpose of this study was to determine the reference ranges of kidney dimensions in preterm newborns and to provide a chart to use easily in daily practice.

MATERIALS AND METHODS

We evaluated renal dimensions in 498 preterm infants with a gestational age of <37 weeks using sonography within the first week of life. We statistically analyzed the relationships between all dimensions and gender, gestational age (based on the last menstrual period), height and weight. Minimum and maximum values of dimensions were defined.

RESULTS

All dimensions of the kidneys were statistically different in boys and girls (P < 0.05). Both longitudinal and anteroposterior dimensions of the right and left kidneys showed high correlation with gestational age, weight and height in girls and boys. Weight correlated best with dimensions.

CONCLUSION

Nomograms from these data can be used to determine an abnormality in kidneys of preterm newborns.