Objective: Fetal insulin concentrations reflect the intrauterine glucose load given the fetus by the mother. In this study, we assessed the association between maternal glucose levels during oral glucose tolerance testing and fetal cord insulin.
Methods: Pregnant women with an oral glucose tolerance test (OGTT) result were included in this prospective study. The patients were divided into 3 groups according to their 1-hour OGTT glucose concentration: up to 160 mg/dL (control, group I), 160-179 mg/dL (intermediate, group II), and gestational diabetes mellitus (GDM, group III). Patients with GDM were assigned to insulin therapy if blood glucose levels were not in the preferable range.
Results: Of the 930 patients who entered the study, 570 (61.3%) were assigned to group I, 76 (8.2%) to group II, and 284 (30.5%) to group III. The cord blood insulin value was significantly (P < .001, Mann-Whitney test) higher in group II (median, 12.8 microU/mL; range, 3-130 microU/mL) than in group I (median, 7.25 microU/mL; range, < 3-98 microU/mL). Cord blood insulin values were higher, albeit not significantly (P = .100, Mann-Whitney test), in group II than in group III (median, 9.9 microU/mL; range, < 3-61 microU/mL).
Conclusion: Children whose mothers had a 1-hour value between 160 and 179 mg/dL had significantly higher cord blood insulin values than offspring of women with a 1-hour value below 160 mg/dL.