Figure 1. The occurrence of GDM in different first-trimester TBA categories.

TBA categories are defined as follows: category 1 (<1.0 μmol/L, n = 71), category 2 (1.0–2.0 μmol/L, n = 354), category 3 (2.0–3.0 μmol/L, n = 188), category 4 (3.0–4.0 μmol/L, n = 76), category 5 (≥4.0 μmol/L, n = 53). *P < 0.05, ***P < 0.001 compared with the first TBA category. The overall P value was less than 0.001.