This study aims to find new plasma biomarkers in early pregnancy.

The original study enrolled 1219 pregnant women. We investigated protein expression profiles of placental tissues from women with GDM (n = 89) and normal glucose tolerance (NGT) (n = 83). Maternal plasma samples between two groups in early and middle pregnancy were used for validation of candidate biomarkers.

Differentially expressed proteins (DEPs) were identified by label-free quantitative proteomics from human placenta samples between two groups. Several DEPs were validated in plasma by Luminex assays. An automatic biochemical analyzer was used to detect blood lipid indexes. The associations of GAL-3BP with biochemical indicators were demonstrated by Pearson's correlation analysis. Binary logistic regression was used to model potential predictive indicators in early pregnancy of GDM. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic accuracy of the predictive model and the value of GAL-3BP.

123 DEPs were found in placenta involved in ribosomal function, pancreatic secretion, oxidative phosphorylation, and inflammatory signaling pathway. Plasma GAL-3BP are significantly higher in women with GDM than NGT in the first (p = 0.008) and second (p = 0.026) trimester, but C9 and VWF have no difference. The predictive value of GAL-3BP in the first trimester of pregnancy (AUC 0.64) is better than that in the second trimester (AUC 0.61), and combined predictive model of TG and GAL-3BP at early pregnancy has greater predictive and diagnostic value for GDM (AUC 0.69) than individual GAL-3BP (AUC 0.64).

Plasma TG and GAL-3BP has good predictive and diagnostic value at early pregnancy, suggesting that these two indicators may be used as biomarkers for early prediction and diagnosis of GDM.

The advantage of this study is that circulating TG and GAL-3BP might differentiate the progress of women with GDM and normal glucose tolerance (NGT) at the early stage of pregnancy. It is the first study to consider the role of GAL-3BP as an early predictive biomarker in the development of GDM during the whole pregnancy. Another advantage is that volunteers in this study were recruited from two provinces in China to eliminate the impacts of environmental confounders. The similar changes of blood glucose/lipid indicators for women with GDM and NGT in both regions was found in the first and second trimester of pregnancy, which added to the reliability of analytical results.