Objective To explore the predictive value of thromboelastography (TEG) for postpartum hemorrhage in pregnant women with gestational thrombocytopenia.Methods A retrospective analysis was conducted on 120 patients with gestational thrombocytopenia treated at Handan First Hospital from June 2022 to June 2024. Patients were divided into two groups based on the occurrence of postpartum hemorrhage: the postpartum hemorrhage group (n = 22) and the non-postpartum hemorrhage group (n = 98). Based on prenatal PLT levels, all patients were categorized into three subgroups: severe thrombocytopenia group (PLT < 50×10?/L, n = 15), moderate thrombocytopenia group (50×10?/L ≤ PLT < 75×10?/L, n = 54), and mild thrombocytopenia group (75×10?/L ≤ PLT < 90×10?/L, n = 51). The thromboelastography parameters, including R-time, K-time, α-angle, maximum amplitude (MA), and coagulation index (CI), were compared among patients with different postpartum hemorrhage outcomes and within different platelet count ranges. Pearson correlation analysis was used to assess the relationship between platelet count (PLT) and TEG parameters, and the predictive efficacy of TEG for postpartum hemorrhage was evaluated.Results A comparison of R value, K value, α angle, MA value, and CI value between the non-postpartum hemorrhage group and the postpartum hemorrhage group showed statistically significant differences (P < 0.05). The R value and K value in the non-postpartum hemorrhage group were lower than those in the postpartum hemorrhage group, while the α angle, MA value, and CI value were higher. Comparison of the R value, K value, α angle, MA value, and CI value among severe thrombocytopenia group, moderate thrombocytopenia group, mild thrombocytopenia group by analysis of variance revealed statistically significant differences (P < 0.05). Pearson correlation analysis showed that the PLT level was negatively correlated with the R value (r = -0.587, P = 0.000) and K value (r = -0.799, P = 0.000), and positively correlated with the α angle (r = 0.624, P = 0.000), MA value (r = 0.764, P = 0.000), and CI value (r = 0.902, P = 0.000). In predicting coagulation function, the combined detection of R, K, α angle, MA, and CI yielded the highest diagnostic efficacy, with an AUC of 0.853 (95% CI: 0.782, 0.925), a sensitivity of 86.7% (95% CI: 0.651, 0.971), and a specificity of 76.2% ( 95% CI: 0.667, 0.845). When the combined detection of R, K, α-angle, MA, and CI was used for postpartum hemorrhage, the AUC was 0.948 (95% CI: 0.877, 1.000), sensitivity was 90.9% (95% CI: 0.708, 0.989), specificity was 96.9% (95% CI: 0.913, 0.994), demonstrating the highest diagnostic efficacy.Conclusion TEG is a valuable tool for predicting postpartum hemorrhage in pregnant women with gestational thrombocytopenia. Combined parameter analysis offers the highest diagnostic efficacy and can provide essential guidance for clinical decision-making.