The neonatal period has one of the highest rates of growth. We prospectively evaluated the roles of C-terminal type 1 collagen propeptide(CICP), bone specific alkaline phosphatase (BSAP) and osteocalcin as potential biochemical markers. Sixteen appropriate for gestational age neonates had cord blood and then weekly CICP, BSAP and osteocalcin levels assayed for 6 weeks; 3 infants were discharged after 4 weeks. None received postnatal steroids. CICP was measured by sandwich immunoassay using monoclonal antibodies, BSAP by using a 2-site immunoradiometric assay and osteocalcin by radioimmunoassay; all in duplicate. Daily weights were recorded and averaged over a week. In utero weight gain was assumed to be 15 gm/kg/day. Data expressed as mean± sem. Using the 2nd order polynomial, change in weight was correlated with CICP (r2= 0.4, p<0.0001), BSAP (r2= 0.006, p= 0.8) and osteocalcin (r2= 0.002, p= 0.9). Based on this pilot study, while BSAP and osteocalcin levels had no correlation, CICP appears to be the most useful biochemical marker of growth. Table

Table 1
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