Correlation Between Maternal and Fetal Insulin Resistance in Pregnant Women with Gestational Diabetes Mellitus

BACKGROUND: Offspring of mothers with gestational diabetes mellitus (GDM) are far more likely to develop type 2 diabetes. The aim of this study was to investigate the effect of the insulin metabolism of pregnant women with GDM in late pregnancy on the insulin metabolism of the fetuses and their correlation. METHODS: This study enrolled 55 pregnant women with GDM and 87 control subjects. Fasting venous blood samples and umbilical venous blood samples (reflecting fetal metabolism) were collected from the study subjects. All blood samples were used to evaluate the blood glucose and insulin concentrations. The blood glucose and insulin concentrations were measured using an automatic biochemical analyser and radioimmunoassay, respectively. The homeostasis model assessment (HOMA) was performed to assess the insulin resistance of mother and fetus. RESULTS: 1. The fasting blood glucose, fasting insulin, and HOMA-IR of pregnant women in the late pregnancy GDM group were all significantly higher than those in the control group (fasting blood glucose: 4.70 ± 0.11 vs. 4.11 ± 0.05 mmol/L, p < 0.001; fasting insulin: 44.1 ± 6.76 vs. 25.1 ± 3.58 µU/mL, p = 0.013; HOMA-IR: 8.92 ± 1.25 vs. 5.39 ± 0.83, p = 0.012); 2. The results of logistic regression analyses showed that maternal age, pre-pregnancy body mass index (BMI), and family history of diabetes were high-risk factors for the development of GDM in pregnant women. 3. The insulin level and HOMA-IR in the umbilical venous blood of the late pregnancy GDM group were both significantly higher than those in the control group (insulin: 10.1 ± 1.41 vs. 6.38 ± 0.49 µU/mL, p = 0.035; HOMA-IR: 1.60 ± 0.22 vs. 1.07 ± 0.08, p = 0.006). 4. The umbilical venous blood HOMA-IR in the GDM group positively correlated with the maternal HOMA-IR and fasting insulin level. The neonatal ponderal index (PI) in the GDM group positively correlated with the umbilical venous blood HOMA-IR and insulin level. CONCLUSIONS: The HOMA-IR was significantly higher in the late pregnancy GDM women and their fetuses than in the control group. In addition, fetal HOMA-IR positively correlated to maternal HOMA-IR in late pregnancy GDM women.