N-Terminal Propeptide of Type-III Procollagen Concentrations in the Cord Blood: An Index of Newborn Maturity

Abstract

Cord serum concentrations of the N-terminal propeptide of type-III procollagen(PIIIP), insulin-like growth factor I (IGF-I), thyroid-stimulating hormone (TSH) and free thyroxine were measured in 149 neonates, consisting of 22 small for gestational age, 95 appropriate for gestational age, 21 large for gestational age and 11 neonates of less than 24 weeks of gestation. Their gestational ages (GAs) ranged from 20 to 41 weeks. A significant negative correlation was found between PIIIP levels and GA (r = ––0.83, p < 0.001). No significant difference was found in PIIIP levels between SGA and LGA neonates, when there were no difference in their GAs, in spite of a significant difference in their birth body weights (p < 0.01). The high concentrations of the cord serum PIIIP did not appear to be influenced by either IGF-I or thyroid hormones, nor was there any relationship between PIIIP and the birth body weight, but only with GA, suggesting that determining cord levels of PIIIP seems to provide a useful parameter for the assessment of newborn maturity.

Markers of collagen metabolism and insulin-like growth factor binding protein-1 in term infants

“…This may reflect differences in somatic growth, and is supported by the correlation between birth weight and lean mass described previously 25. These results are in contrast with a report by Yunoki et al ,9 in which no significant difference was found in this variable between LGA and SGA infants. This discrepancy may be due to different selection of subjects, as the previous report included neonates of 20–41 weeks of gestation 9…”

“…At birth, small for gestational age (SGA) infants have lower concentrations of PIIINP than infants appropriate for gestational age (AGA) 8. However, the opposite has also been found 9. Different results have been reported on the relation between fetal growth status and circulating concentrations of collagen propeptides at birth.…”

Type I collagen markers in cord serum of appropriate vs. small for gestational age infants born during the second half of pregnancy

“…These findings are in accordance with those obtained in another study of PIIINP levels [22], but differ from the observation by Yunoki et al . that there is no difference in PIIINP values between AGA and SGA infants [24]. Due to the variation it is hard to assess the significance of a single low PINP value in a clinical setting.…”