Systemic inflammatory indices as predictors of adverse outcomes in pregnancies with vascular events: A retrospective cohort study

OBJECTIVE: To investigate the association between systemic inflammatory indices, including the systemic immune-inflammation index (SII), systemic inflammation response index (SIRI), and aggregate index of systemic inflammation (AISI), and vascular events during pregnancy, and to evaluate their association with maternal disease severity, particularly maternal intensive care unit (ICU) requirement. METHODS: This retrospective cohort study included pregnant and postpartum women with vascular events and gestational age-matched controls without vascular events. Inflammatory indices were calculated using first-trimester laboratory parameters and values obtained at the time of vascular event diagnosis. Group comparisons were performed using non-parametric tests, and receiver operating characteristic (ROC) curve analyses were conducted to assess the predictive performance of inflammatory indices for maternal ICU requirement. RESULTS: First-trimester inflammatory indices (SII-1, SIRI-1, and AISI-1) and delta (Δ) values did not differ significantly between groups. In contrast, inflammatory indices measured at the time of vascular event diagnosis (SII-2, SIRI-2, and AISI-2) were significantly higher in women who experienced vascular events. These indices were not associated with composite adverse perinatal outcomes (CAPO), neonatal intensive care unit (NICU) admission, or maternal sequelae. However, all three indices were significantly associated with maternal ICU requirement. Among them, SIRI-2 demonstrated the strongest discriminatory performance for predicting maternal ICU admission (area under the curve: 0.911). CONCLUSION: Systemic inflammatory indices measured at the time of vascular event diagnosis may be associated with maternal disease severity but not with adverse perinatal outcomes; however, further prospective studies are needed to confirm their clinical utility.