Bone measurements of infants in the first 3 months of life by quantitative ultrasound: the influence of gestational age, season, and postnatal age.

Background: There are a few quantitative ultrasound (QUS) studies of bone status for Chinese children.

Objective: To evaluate the clinical application and to investigate the bone status of neonates and young infants with QUS.

Materials And Methods: An ultrasound bone sonometer was used to measure the bone speed of sound (SOS) of the tibia in 542 neonates within 3 months of birth.

Results: At birth, no significant difference of SOS was found between boys and girls, but there was a significant difference of SOS between premature infants and full-term infants. The SOS in neonates born during spring and summer was significantly lower than those born during autumn and winter. There were significant correlations between SOS and gestational age, and between bone SOS and birth weight in appropriate for gestational age (AGA) infants. Multiple regression analysis found that gestational age and infant birth season were two important factors influencing SOS. During the first 3 months, there was no significant difference in SOS between sexes. The SOS of infants showed an inverse correlation with postnatal age, and the decrease of bone SOS with age in premature infants was more marked than in full-term infants.

Conclusions: QUS is suitable for evaluating bone status in infants with high precision. The study offers some basic data for neonates and young infants.