Objective To investigate the correlation between neonatal birth indicators and bone age(BA) development in children.

Methods A total of 258 neonates were selected as the study subjects, and 60 neonates participated in the subsequent physical examination at the age of 4.All subjects underwent X-rays of the left hand to calculate the bone age progress indexratio of BA to chronological age(CA) (BA/CA).The association between growth variables at birth and BA/CA was evaluated using the Pearson correlation analysis.Linear regression was used to analyze the effects of growth variables on the BA/CA at 4 years of age.

Results The 42.9% of the lowest birth weight group remained at the lowest weight group after 4 years.About 78.6% of those with the lowest birth weight were in the highest conditioned weight gain group at age 4, and 68.8% of those with the highest birth weight were in the lowest conditioned weight gain group at age 4.The BA/CA was positively correlated with birth weight(r=0.412, P < 0.01).The results of multiple linear regression analysis showed that BA/CA increased with birth weight.After adjusting the sex, gestational age and height at age 4, the BA/CA increased with birth weight and conditional body mass(P < 0.05).

Conclusions Neonate birth weight and subsequent growth acceleration are associated with an increased risk of early BA in young children.