OGTT in Early Pregnancy May Predict Gestational Diabetes Risk, Suggests Study
Switzerland: Researchers have found in a new study that a 75 g OGTT conducted at around 13 weeks of pregnancy can help identify women at high risk for developing gestational diabetes mellitus (GDM). The 60-minute glucose value showed the strongest predictive accuracy (AUROC 0.74), followed by 120-minute (0.72) and fasting (0.68). Early OGTT results were also linked with impaired insulin sensitivity, beta-cell dysfunction, and the likelihood of future insulin requirements.
The study, published in Diabetologia by Evelyn A. Huhn and colleagues from the Department of Obstetrics and Gynaecology, University Hospital Basel, Switzerland, explored whether conducting an OGTT early in pregnancy could offer reliable risk stratification for later development of GDM. Traditionally, screening for GDM is performed between 24–28 weeks of pregnancy, but there has been growing interest in whether earlier testing could help in identifying at-risk women sooner.
For this purpose, the researchers conducted a prospective cohort study involving 657 pregnant women across six Central European centers. A blinded 75 g OGTT was carried out at a median gestational age of 13.4 weeks, along with the collection of patient history, anthropometric measurements, and biochemical markers. A repeat OGTT was later performed to diagnose GDM in the second or third trimester. In addition, a subgroup of women underwent a detailed analysis of glucose homeostasis at both time points.
The ley findings were as follows:
- Out of the total participants, 83 women (12.6%) developed gestational diabetes mellitus (GDM) during pregnancy.
- Glucose levels measured at different time points during the early OGTT were effective predictors of GDM risk.
- The 60-minute glucose reading showed the highest predictive accuracy (AUROC 0.74).
- The 120-minute glucose value had an AUROC of 0.72, while fasting glucose had 0.68.
- Compared to other biomarkers such as maternal age and pre-pregnancy BMI, early OGTT results showed superior performance in forecasting disease risk.
- Early OGTT readings were associated with impaired insulin sensitivity.
- They were also linked to beta-cell dysfunction.
- Women with higher early OGTT readings were more likely to require insulin therapy later in pregnancy.
- These findings suggest that early glucose dynamics not only indicate GDM risk but also reflect underlying metabolic disturbances.
The authors emphasized that while precise diagnostic thresholds for GDM in the first trimester are yet to be determined, their findings highlight the potential of early OGTT as a valuable clinical tool. By identifying women at high risk earlier, healthcare providers could design timely interventions aimed at preventing or mitigating adverse outcomes.
However, the study acknowledged certain limitations, particularly that it was not specifically designed to establish or validate glucose cut-off values in early pregnancy. The researchers noted that future studies are needed to refine these thresholds and assess whether early interventions can improve maternal and neonatal outcomes.
"The study suggests that performing a 75 g OGTT in the first trimester offers meaningful insights into a woman’s metabolic status and can help predict the likelihood of developing GDM as well as the need for insulin therapy later in pregnancy. These findings support the use of early OGTT as an important tool for risk stratification in antenatal care," the researchers concluded.
Reference:
Huhn, E.A., Kotzaeridi, G., Fischer, T. et al. The utility of early gestational OGTT and biomarkers for the development of gestational diabetes mellitus: an international prospective multicentre cohort study. Diabetologia (2025). https://doi.org/10.1007/s00125-025-06517-0
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