Objective: To determine the possible relation between maternal serum insulin-like growth factor I and II (IGF-I and IGF-II) in women with insulin-dependent diabetes mellitus and fetal macrosomia.
Methods: This was a prospective, observational study of 45 pregnant women with insulin-dependent diabetes mellitus without overt nephropathy, examined in an outpatient, antenatal diabetic clinic. Maternal venous serum samples were collected from week 14 every fourth week until week 30, and every other week until delivery. Levels of IGF-I and -II were measured in maternal serum by immunoassays. The repeated measurements were tested with two-way analysis of variance. The outcome measures were birth weight and serum IGF-I, IGF-II, IGF binding protein (BP)-3, and IGFBP-3 proteases. Before the study, minimum sampling size was calculated as 14 subjects in each group if a difference in IGF-I of 50 microg/L was to be detected with an estimated standard deviation of 40, a two-sided P value (alpha) of.05, and a power of 90 (beta =.1).
Results: Increasing levels of IGF-I and -II were significantly associated with the birth-weight groups: The higher the birth-weight ratio, the higher the levels of IGF-I and -II (P <.01).
Conclusion: Macrosomia in diabetic pregnancy is associated with high levels of maternal IGF-I and -II.