Objective To investigate the changes in the expression levels of serum glutathione peroxidase 3 (GPX3) and aquaporin 9 (AQP9) in pregnant women with gestational diabetes mellitus (GDM) and their relationships with pregnancy outcomes.

Methods A total of 200 pregnant women with GDM (GDM group) and 200 healthy pregnant women (control group) were enrolled as study subjects. The GDM group was further divided into adverse pregnancy outcome (APO) subgroup(n=22) and favorable pregnancy outcome subgroup(n=178) based on pregnancy outcomes. The expression levels of serum GPX3 and AQP9 were detected by enzyme-linked immunosorbent assay. Multivariate Logistic regression analysis was used to screen for influencing factors of APO in GDM pregnant women. Receiver operating characteristic (ROC) curves were plotted to analyze the predictive performance of serum GPX3 and AQP9 expression levels for APO in GDM pregnant women.

Results Compared with the control group, the serum GPX3 expression level was decreased, and the serum AQP9 expression level was increased in the GDM group (P < 0.05). The incidence of APO among the 200 GDM pregnant women was 11.00%(22/200). Compared with the favorable pregnancy outcome subgroup, the APO group had higher levels of homeostasis model assessment-insulin resistance index (HOMA-IR), fasting blood glucose, glycated hemoglobin (HbA1c), and AQP9, and lower levels of GPX3 (P < 0.05). Multivariate Logistic regression analysis revealed that elevated HOMA-IR, HbA1c, and AQP9 were independent risk factors for APO in GDM pregnant women (P < 0.05), while elevated GPX3 was an independent protective factor (P < 0.05). The ROC curve showed that the areas under the curve (AUCs) for predicting APO in GDM pregnant women were 0.784 (95%CI, 0.673 to 0.881) for serum GPX3 alone, 0.788 (95%CI, 0.687 to 0.894) for serum AQP9 alone, and 0.906 (95%CI, 0.805 to 0.972) for their combination, with the AUC for the combined prediction being greater than that for individual prediction (P < 0.05).

Conclusion The serum GPX3 expression level is decreased, and the serum AQP9 expression level is increased in GDM pregnant women. Both serum GPX3 and AQP9 are independent influencing factors for APO, and their combined prediction has a higher value for APO in GDM pregnant women.