ASSOCIATION OF LATE POST-LOAD GLUCOSE LEVELS DURING ORAL GLUCOSE TOLERANCE TESTING WITH FETAL MACROSOMIA

Background: Maternal hyperglycemia is associated with excessive fetal growth, but the relative importance of individualglucose values during oral glucose tolerance testing (OGTT) remains uncertain. This study evaluated the association offasting and post-load glucose values with fetal macrosomia, with particular attention to later post-load glucose. Materialsand Methods: This secondary analysis included 100 pregnant women with available OGTT and delivery outcome data.Fasting, 1-hour, 2-hour and exploratory 3-hour glucose values were assessed in relation to macrosomia. Firth penalizedlogistic regression was used because only eight macrosomia events were present. Adjusted models included maternal age,BMI and primigravida status. The 2-hour and 3-hour glucose values were also analysed by tertiles. Receiver operatingcharacteristic analysis was performed and AUCs were compared using DeLong’s test. Results: Macrosomia occurred ineight participants. Higher 2-hour and 3-hour glucose showed increased odds of macrosomia, with adjusted ORs of 1.31 and1.32 per 10 mg/dL increase, respectively, although these associations were not statistically significant. Macrosomiaincreased from 0% in the lowest 2-hour glucose tertile to 15.2% in the highest tertile (p=0.053). For 3-hour glucose,macrosomia was 18.2% in the highest tertile compared with approximately 3% in the lower tertiles (p=0.039). The AUC was0.726 for 2-hour glucose and 0.732 for 3-hour glucose, with no significant difference between them (p=0.903). Conclusion:Higher late post-load glucose levels showed a possible association with fetal macrosomia. Both 2-hour and 3-hour glucosedemonstrated moderate and similar discriminatory ability. The 3-hour value was not superior to the 2-hour measurement andshould be considered exploratory.