Objective: We hypothesize that the balance of maternal and fetal insulin-like growth factor-I (IGF-I) concentrations contributes to the regulation of substrate distribution between mother and fetus, and may thus mediate the maintenance of blood ferritin concentration in the fetus. Therefore, the relationship between cord blood IGF-I to ferritin concentration was investigated.
Infants and methods: Twenty-six term neonates were recruited. Anthropometric measures were recorded and umbilical cord blood samples were collected at birth. We studied serum concentrations of IGF-I in relation to blood ferritin and anthropometric data in term neonates. To assess the importance of the correlation of ferritin with both IGF-I and all other parameters, multiple linear regression analysis was carried out, with ferritin as the dependent variable and IGF-I and anthropometric parameters as independent variables.
Results: The mean concentrations of cord blood IGF-I and ferritin levels were 45.2 +/- 36.8 ng/ml and 225.5 +/- 124.2 ng/ml, respectively, at birth. A positive correlation was observed between IGF-I and ferritin concentrations of term neonates (r = 0.53, p = 0.005). IGF-I emerged as a significant predictor of ferritin concentration (beta = 1.79, p = 0.005) contributing to 28% of its variability.
Conclusions: We showed a relationship between cord blood IGF-I and ferritin levels in term neonates, suggesting that even within an unremarkable population, fetal ferritin level may be influenced by IGF-I. Moreover, we speculated that IGF-I might also be important in the regulation of placental transport of ferritin.