Macrosomia associated with maternal serum insulin-like growth factor-I and-II in diabetic pregnancy

Objective: To determine the possible relation between maternal serum insuli n-like growth factor I and II (IGF-I and IGF-II) in women with insulin-depe ndent diabetes mellitus and fetal macrosomia. Methods: This was a prospective, observational study of 45 pregnant women w ith 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 oth er week until delivery. Levels of IGF-I and -II were measured in maternal s erum by immunoassays. The repeated measurements were tested with two-way an alysis of variance. The outcome measures were birth weight and serum IGF-I, IGF-II, IGF binding protein (BP)-3, and IG-FBP-3 proteases. Before the stu dy, minimum sampling size was calculated as 14 subjects in each group if a difference in IGF-I of 50 mug/L was to be detected with an estimated standa rd 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 w ith 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 ICF-I and -II. (Obstet Gynecol 2001;97:734-41. (C) 2001 by The American College of Obstetricians and Gynecologists.).