Current early pregnancy screening tools to identify women at risk of developing 
gestational diabetes mellitus lack both specificity and sensitivity. As a 
result, the foetus and mother are often subjected to insult during disease 
progression, prior to diagnosis and treatment in later pregnancy. Metabolomics 
is an analytical approach, which allows for appraisal of small molecular mass 
compounds in a biofluid. The aim of this pilot study was to investigate the 
relationship between the early gestation serum metabolite profile and the 
subsequent development of gestational diabetes mellitus in the search for early 
pregnancy biomarkers and potential metabolic mechanisms. Our nested case-control 
study analysed maternal serum at 20 weeks' gestation, obtained from the New 
Zealand cohort of the Screening for Pregnancy Endpoints study. Metabolomic 
profiling was performed using gas chromatography coupled to mass spectrometry, 
and metabolites were identified using R software and an in-house mass spectral 
library. Statistical analysis was performed using SPSS version 21.0. Forty-eight 
metabolites were identified in the serum samples. Itaconic acid (P = 0.0003), 
with a false discovery rate of 0.012, was found to be significantly more 
abundant in women who subsequently developed gestational diabetes mellitus, when 
compared to controls with uncomplicated pregnancies. The current pilot study 
found that itaconic acid may have potential as a novel biomarker in early 
pregnancy to predict the subsequent development of gestational diabetes 
mellitus. However, the findings from this pilot study require validation with a 
larger, diverse population before translation into the clinical setting.