Maternal-fetal glucose metabolism and fetal growth retardation. Is there an association?

OBJECTIVE: To test the hypothesis that in normotensive pregnancies decreased maternal glucose response leads to relative fetal hypoglycemia and hypoinsulinemia, which result in delayed fetal growth. STUDY DESIGN: We enrolled patients with and without risk factors for growth retardation. Each underwent an oral glucose tolerance test with both glucose and insulin evaluation. Cord blood was obtained for glucose and insulin evaluation. RESULTS: The normotensive pregnancies at risk had lower maternal glucose levels (index, 91 vs. 116 mg/dL; P < .05), a trend toward lower maternal insulin levels (index, 398 vs. 483 muIU/mL; P = NS) and normal maternal insulin/glucose ratios. We found no differences, however, in the fetal metabolic parameters (glucose 83 vs. 78 mg/dL, insulin 17 vs. 24 muIU/mL; P = NS). CONCLUSION: Maternal glucose metabolism is altered in nonhypertensive pregnancies, with a risk of delayed fetal growth; however, the fetal glucose response may remain normal in the face of fetal growth retardation.