GPT and oligohydramnios: In the training set, univariate analysis showed that there were statistically significant differences between the placental abruption group and the non-placental abruption group in terms of primiparity, systolic blood pressure, diastolic blood pressure, 24-h quantitative proteinuria, blood uric acid, serum creatinine, blood urea nitrogen, ALT, AST, uterine artery blood flow resistance index, umbilical artery blood flow resistance index, serum APN, serum Cys-C, serum D-dimer, fetal growth restriction, and oligohydramnios (all p < 0.05) (Table 2).