Nutritional and inflammatory indices in gestational and pregestational diabetes: emphasis on the Controlling Nutritional Status (CONUT) score.

OBJECTIVE: To comparatively evaluate the prognostic value of nutritional and inflammatory indices in gestational diabetes mellitus (GDM) and pregestational diabetes mellitus (PGDM), and to determine their association with adverse perinatal outcomes. METHODS: This retrospective study included 280 pregnant women followed at a tertiary care center between January 2020 and December 2024. Participants were categorized into three groups: GDM (n = 90), PGDM (n = 80), and healthy controls (n = 110). Nutritional status was assessed using the Controlling Nutritional Status (CONUT) and Prognostic Nutritional Index (PNI) scores. Inflammatory indices including NLR, SII, SIRI, PIV, and others were calculated. Perinatal outcomes such as preterm birth, NICU admission, and Composite Adverse Perinatal Outcomes (CAPO) were recorded. ROC analysis was used to determine the predictive power of the biomarkers. RESULTS: The PGDM group demonstrated significantly higher CONUT scores and lower PNI scores compared to the other groups (p < 0.001). Among inflammatory markers, NLR, SII, SIRI, and PIV were significantly elevated in PGDM cases. ROC analyses revealed that the CONUT score had strong discriminative ability in differentiating diabetic (GDM and PGDM) from non-diabetic pregnancies (AUC = 0.787; specificity = 89.1%), while the PNI score showed limited discriminative capacity (AUC = 0.291). Inflammatory indices also demonstrated moderate predictive value, particularly among PGDM cases. Higher CONUT and inflammatory scores were associated with increased rates of preterm birth, NICU admission, and CAPO (p < 0.001). CONCLUSION: Nutritional and inflammatory disturbances are more prominent in PGDM than in GDM. The CONUT score and selected inflammatory indices may serve as valuable tools for early risk stratification in diabetic pregnancies. Integration of these parameters into clinical decision-making may improve perinatal outcomes, particularly in high-risk groups such as PGDM.