Bone ultrasound velocity curves of newly born term and preterm infants.

BACKGROUND Ultrasound velocity (speed-of-sound [SOS]) has been proposed as a non-invasive method of evaluation of bone status in infants. We hypothesized that SOS correlates with both gestational age and birth weight. METHODS We measured SOS within the first 96 hours of life at the right tibial midshaft location in 73 neonates ranging in gestational age from 25 to 41 weeks, and in birth weight from 825 to 3880 grams. We used the Sunlight Omnisense 7000p device (Tel Aviv, Israel). Results are expressed as meanS +/- 1 SD; statistical analyses included linear regression and computation of 95% CI regression lines; p<0.05 was considered significant. RESULTS There was, as hypothesized, a significant correlation between gestational age (or birth weight) and SOS. There were no significant differences between males and females. Ninety-five percent confidence intervals were established. CONCLUSIONS These data may be used as reference ranges for further studies.