Elevated neonatal insulin-like growth factor I is associated with fetal hypertrophic cardiomyopathy in diabetic women.

OBJECTIVE: We sought to determine if fetal hypertrophic cardiomyopathy (HCM) or cardiac dysfunction is associated with elevated maternal or neonatal insulin-like growth factor (IGF)-I levels in women with diabetes. STUDY DESIGN: In a prospective cohort study, fetal echocardiogram findings at 36 weeks' gestation in women with pregestational diabetes mellitus were compared to those in women without diabetes mellitus. HCM was defined as septal or free wall thickness >= 5 mm and cardiac dysfunction as a modified myocardial performance index >= 0.43. Cord serum IGF-I levels at delivery were measured with enzyme-linked immunosorbent assay. Neonates with abnormal fetal echocardiogram were followed up until resolution or 6 months of life. RESULTS: In all, 75 participants completed fetal echocardiography (55 diabetics and 20 controls). In the diabetic group, 33 of 55 (60%) had abnormal fetal echocardiograms with cardiac dysfunction in 21 of 55 (38.2%) and HCM in 8 of 55 (14.5%) and both in 4 of 55 (7.3%). At 6 months of age, 1 of 12 (8%) had persistent HCM. None in the comparison group had abnormal findings. There were no significant clinical differences in those diabetic women with normal vs abnormal fetal echocardiograms. However, among diabetic women, mean neonatal IGF-I was significantly higher in fetuses with HCM (80 +/- 16 ng/mL) as compared to those without HCM (61 +/- 18 ng/mL), (P < .001). CONCLUSION: Elevated neonatal IGF-I appears to be associated with fetal HCM in fetuses of diabetic women.