A new reference line for measuring the liver size in healthy newborns.

The liver span in 103 healthy newborns was determined by percussion and ultrasonic scanning along the midclavicular line (MCL) and the umbilicus-nipple line (UNL). The liver size (mean +/- SD) measured along the MCL was 4.1 +/- 0.7 cm (range 2.7-5.7 cm) by percussion and 4.0 +/- 0.8 cm (range 1.9-6.2 cm) by ultrasonic scanning. Along the UNL, the liver size determined by percussion was 4.0 +/- 0.7 cm (range 2.8-5.8 cm) and 3.7 +/- 0.8 cm (range 1.4-5.8 cm) by ultrasonic scanning. The correlation coefficient between liver measurement along the MCL and UNL by percussion and ultrasonic scanning was good and statistically significant (r = 0.95, p < 0.0001 and r = 0.83, p < 0.02, respectively). The new reference line for measuring the liver size, the UNL, should allow the clinician to determine the liver size more easily and may improve the accuracy in examining the liver.