Early screening and diagnosis are important for minimizing gestational adverse outcomes. Routine screening of gestational diabetes mellitus (GDM) at 24-28 weeks with 75 g oral glucose challenge test (OGCT) leaves limited time for intervention and prevention. This study aims to analyze maternal serum peptides in the early second-trimester for prediction of gestational diabetes mellitus (GDM)

Gestational diabetes mellitus (GDM) is defined as a condition in which carbohydrate intolerance develops during pregnancy. As rates of obesity and diabetes have increased rapidly in recent years, the prevalence of GDM is also increasing and is now estimated at 1.7%-11.6 %.

Currently, there is no consensus as to the ideal screening method for GDM. The two competing approaches are the “2-step and the ‘‘1-step” approaches. The 2-step approach begins at about 24 to 28 weeks’ gestation with an oral glucose challenge test (OGCT). This is followed by a 3-hour OGTT. The 1-step approach consists of a 2-hour OGTT only.

Serum samples were collected from 16-18-week pregnant women that visited Nanjing Maternity and Child Health Care Hospital from April to August 2015. 

GDM biomarkers 

According to the gestational outcome with or without GDM in late pregnancy, 200 of serum samples from GDM mothers and controls were randomly divided into two subgroups.

Peptidomic identification of serum peptides was performed by combining ultrafiltration and liquid chromatography-tandem mass spectrometry (LC-MS/MS) to investigate the differentially-expressed peptides between two groups.

A total of 297 identified peptides, originating from 228 proteins, were significantly differentially expressed in the GDM group compared with control. These precursor proteins may play critical roles in cell death of cortical neurons, elongation of cellular protrusions, and stabilization of microtubules. Major networks identified included those involving lipid metabolism, molecular transport, and small molecule biochemistry.

Human serum is a rich source of endogenous peptides, many of which may serve as biomarkers. However, relatively few studies have explored the potential of this class of molecules as a source of GDM biomarkers. In this study, we focused on early detection and identification of alterations in peptide profiles between GDM patients and healthy controls.

We provide for the first time a validated peptidome profile of early second-trimester serum in normal and GDM mothers, and we investigated the potential serum biomarkers for GDM. We concluded that 297 peptides could serve as potential biomarkers for GDM.