Gestational diabetes mellitus (GDM) is a common pregnancy complication that increases maternal and fetal risks. Early detection through reliable biomarkers may enable timely intervention. Asprosin, a newly identified adipokine, shows potential as a predictor of GDM but has not been evaluated in the first trimester. Glycated hemoglobin (HbA1c), reflecting average blood glucose over 2–3 months, may also assist in assessing early glycemic status. This study aimed to evaluate the performance of first-trimester asprosin and HbA1c levels in predicting GDM.

This prospective cohort study was conducted on singleton pregnant women at 10–13⁺⁶ weeks of gestation at Chiang Mai University Hospital between February and November 2025. Women with pre-gestational diabetes, first-trimester HbA1c ≥6.5%, or the use of glucose-affecting medications were excluded. Clinical data, such as maternal age, body mass index (BMI), obstetric history, and medical risk factors, were collected. Blood samples were obtained for asprosin measurement using an enzyme-linked immunosorbent assay and for HbA1c assessment using a turbidimetric inhibition immunoassay. Participants underwent GDM screening and diagnosis at 24–28 weeks of gestation using a two-step approach, as a gold standard. Univariable and multivariable models incorporating asprosin, HbA1c, and relevant clinical factors were constructed and their predictive performance compared using receiver operating characteristic (ROC) analysis.

A total of 190 women were enrolled, of whom 67 (35.3%) were diagnosed with GDM. Women who developed GDM were significantly older (p=0.002) and had higher BMI (p=0.010) and pre-pregnancy weight (p=0.002) compared with those without GDM. A first-degree family history of diabetes (p=0.023) and a history of dyslipidemia (p=0.006) were also more frequent in the GDM group. First-trimester HbA1c levels were significantly higher in the GDM group (5.3±0.4% vs. 5.1±0.3%, p<0.001), whereas asprosin levels did not differ significantly, although they tended to be lower (57.6±16.9 vs. 60.9±20.1 ng/mL, p=0.253). In ROC analysis, HbA1c demonstrated moderate predictive ability (AUC=0.623), while asprosin showed limited predictive value (AUC=0.519). The combined model incorporating HbA1c, age, and BMI improved prediction (AUC=0.723), whereas adding asprosin did not yield additional benefit.

First-trimester asprosin offers minimal predictive value for GDM and is not suitable for screening purposes, whereas HbA1c provides moderate accuracy. Combining HbA1c with maternal age and BMI further enhances early GDM prediction.