Objective: To estimate the association between fasting and 2-hour postprandial blood glucose levels and neonatal outcomes in women treated for mild gestational diabetes.
Methods: In this secondary analysis of a multicenter randomized treatment trial of mild gestational diabetes, the median fasting and 2-hour postprandial glucose levels were analyzed in 2-week intervals and change over time (slope) was calculated for women with gestational diabetes (abnormal oral glucose tolerance test) and a fasting glucose less than 95 mg/dL who received nutritional management with self blood glucose monitoring and insulin as needed. Regression analyses were performed to estimate the relationship between median fasting and postprandial glucose and neonatal fat mass, cord blood C-peptide, birth weight, large-for-gestational-age neonates, macrosomia (greater than 4,000 g), and neonatal hypoglycemia.
Results: Among 460 women with gestational diabetes, median fasting (P<.001), postprandial breakfast (P<.001), and postprandial lunch (P<.001) glucose values declined over the treatment period, whereas postprandial dinner values remained stable (P=.83). Higher median fasting glucose during the first 2 weeks of treatment was significantly associated with increased odds ratios for neonatal fat mass (1.35; 95% CI 1.09-1.66; P=.006) and elevated C-peptide (1.29; CI 1.09-1.52; P=.003). Higher median fasting glucose during the last 2 weeks before delivery was associated with higher rates of large-for-gestational-age neonates (1.27; CI 1.05-1.53; P=.01), macrosomia (1.32; CI 1.04-1.65; P = .02), and elevated C-peptide (1.19; CI 1.03-1.38; P=.02).
Conclusion: In women treated for mild gestational diabetes, higher fasting glucose during initiation of diet therapy was associated with increased neonatal fat mass and elevated C-peptide and during the last 2 weeks before delivery with macrosomia, large-for-gestational age, and elevated C-peptide.
Level of evidence: II.