Objective: To investigate how 100-g oral glucose tolerance test (OGTT) results can be used to predict adverse pregnancy outcomes in pregnant women. Design: Retrospective cohort. Setting and sample: Single-center with 1,059 pregnant women Main outcome measures: A composite of adverse pregnancy outcomes including preterm birth, macrosomia, large for gestational age, low “appearance, pulse, grimace, activity, and respiration” score at 1 min, and pregnancy-induced hypertension. Methods: We compared the risk of adverse pregnancy outcomes according to OGTT patterns by latent profile analysis (LPA), numbers to meet the OGTT criteria, and area under the curve (AUC) of the OGTT graph. Results: Overall, 257 participants were diagnosed with GDM, with a median age of 34 years. An LPA led to three different clusters of OGTT patterns, however, there were no significant associations between the clusters and adverse pregnancy outcomes after adjusting for confounders. Notwithstanding, the risk of adverse pregnancy outcome increased with an increase in number to meet the OGTT criteria (p for trend = 0.011); odds ratios in a full adjustment model were 1.27 (0.72–2.23), 2.16 (1.21–3.85), and 2.32 (0.66–8.15) in those meeting the 2, 3, and 4 criteria, respectively. The AUCs of the OGTT curves also distinguished the patients at risk of adverse pregnancy outcomes; the larger the AUC, the higher the risk (p for trend = 0.007). Conclusions: The total number of abnormal values and calculated AUCs for the 100-g OGTT may facilitate precise management of patients with GDM by predicting adverse pregnancy outcomes.