Cord C-peptide and insulin-like growth factor-I, birth weight, and placenta weight among North African and Belgian neonates

Objective Despite their low socioeconomic status, infants of North African immigrants have been reported to have high birth weights in Belgium. The aim of the study was to further explore potential mechanisms explaining this high birth weight. Study design Venous umbilical cord blood samples and perinatal characteristics of live-born infants from mothers of North African and Belgian nationality were collected in 1997 through 1998 at the University Hospital La Citadelle, Liège, Belgium. Results The median connecting peptide (C-peptide) concentration was significantly higher among North African than Belgian neonates (0.125 vs 0.110 pmol/mL, P = .04). However, the median insulin-like growth factor-I concentrations among North African and Belgian newborn infants were, respectively, 74.0 and 69.6 ng/mL (P = .45). Nationality remained significantly associated with C-peptide after adjusting for age and parity. C-peptide, insulin-like growth factor-I correlated positively with birth weight and remained significant factors for birth weight after adjusting for confounders in multiple regression. Conclusion These results suggest a link between higher C-peptide levels and birth weights among North African neonates in Belgium.