The predictive value of the first–trimester aggregate index of systemic inflammation ( AISI ) in gestational diabetes mellitus in women with twin pregnancies: A prospective cohort study

Abstract Objective To investigate the association between the first–trimester aggregate index of systemic inflammation (AISI) and the risk of gestational diabetes mellitus (GDM) in women with twin pregnancies, and to evaluate the predictive value of this novel index. Methods A prospective cohort study was conducted in Maternal and Child Health Hospital of Hunan Province from January 2019 to December 2024, enrolling 335 women with twin pregnancies during their first trimester of pregnancy (7–14 weeks) after exclusions. Multivariable logistic regression, restricted cubic spline (RCS) models, receiver operating characteristic (ROC) curves, subgroup analyses, and sensitivity analyses were used to evaluate associations, diagnostic effects, and consistency of the study. Results AISI was significantly and positively associated with the risk of GDM. After fully adjusted, the risk of GDM was significantly higher in the highest quartile compared with the lowest of AISI (odds ratio [OR]: 2.11, 95% confidence interval [CI]: 2.11 [1.07–4.19]; P = 0.032). A non‐linear dose–response relationship was identified ( P for nonlinear = 0.020). ROC analysis demonstrated a diagnostic accuracy with an area under the curve (AUC) of 0.61 (95% CI: 0.54–0.69, cutoff point = 610.65). The associations remained consistent in sensitivity analyses and most of the subgroup analyses ( P for interaction >0.05). Conclusion Elevated first–trimester AISI levels are independently associated with an increased risk of GDM in twin pregnancies. AISI may serve as a potential indicator for early prediction of GDM in this unique population.