Association between fetal insulin-like growth factor I and macrosomia in diabetic pregnancy

Objectives This study aimed to determine whether fetal insulin-like growth factor I (IGF-I) is associated with macrosomia in well-controlled diabetic pregnancy. Methods Infants of 26 diabetic mothers, 14 with insulin-dependent diabetes mellitus (IDDM) and 12 with gestational diabetes mellitus (GDM), with good metabolic control and 26 newborn children of healthy mothers were investigated. Cord IGF-I and C-peptide levels were determined at delivery and were correlated to gender and gestational age-adjusted relative birth weight and length ratios. Results A high incidence of macrosomia (birth weight more than +2 SD) was found in infants of diabetic mothers (42%), compared to none in the control group. The cord C-peptide and IGF-I levels were significantly higher in children of diabetic mothers than in those of healthy mothers. We found no correlation between cord C-peptide or maternal hemoglobin A(1c) and the relative birth weight ratio. A significant correlation was found between cord IGF-I and the relative birth weight and length ratios in children of diabetic mothers (r = 0.64, p = 0.0007; r = 0.59, p = 0.0025, respectively). Conclusions These findings suggest that ICF-I is associated with the development of macrosomia in well-controlled diabetic pregnancies.