Abstract: ［Abstract］〓Objective〖HTSS〗〓To investigate the role and significance of aminoterminal proCtype natriuretic peptide(NTproCNP), bone specific alkaline(BAP) and osteocalcin(OC) in boneformation of neonates with different gestational age.
〖HTH〗〖WTHZ〗Methods〖HTSS〗〓Eighty cases of neonates born within 24 hours were selected and were divided into group A(gestational age<32 weeks), group B(32 weeks ≤gestational age<37 weeks), and group C(37 weeks ≤ gestational age<42 weeks) according to gestational age. According to the body length participants were divided into three groups: length less than that of gestational age group(L1 group), length appropriate for gestational age group(L2 group), and length greater than the gestational age group(L3 group). According to body weight percentile, they were divided into three groups: body weight less than that of gestational age group(W1 group), body weight appropriate for gestational age group(W2 group), and body weight greater than gestational age group(W3 group). Birth length and body mass were measured within 1 hour after birth. Serum NTproCNP, BAP and OC were measured within 24 hours after birth.
〖HTH〗〖WTHZ〗Results〖HTSS〗〓There were no significant differences in gestational age, birth length, body mass, NTproCNP, BAP and OC between male and female neonates(P＞005). Participants from group B and C had higher  birth length and body weight than A group. Participants from group C had higher birth length and body weight than group B. BAP of group C was lower than that of group A and B(P＜005). There was no significant difference in gender, NTproCNP and OC among 3 groups(P＞005). BAP of group L3 was lower than that of group L1 and L2(P＜005). There was no significant difference in the levels of NTproCNP and OC among 3 groups(P＞005); NTproCNP, BAP and OC level had no significant difference among group W1, W2 and W3(P＞005). Neonatal birth weight and body length were positively correlated with gestational age(P＜005). There were no correlation between NTproCNP and OC and gestational age, birth weight and BAP(P＞005). BAP and gestational age, body weight, and body length were negatively correlated(P＜005).
〖HTH〗〖WTHZ〗Conclusion〖HTSS〗〓No relationship between serum NTproCNP levels and fetal bone development during the second and third trimester of pregnancy was found. BAP is closely correlated with fetal bone growth and development. With the increase of gestational age, fetal ossification gradually weakened. The mineralization of fetal bone is weak and the bone strength of newborn is samll, which may be beneficial to delivery.

Key words: bone development, natriuretic peptide, Ctype, osteogenic markers, infant, newborn