Platelet and Inflammatory Indices as Predictors of Adverse Perinatal Outcomes in Behçet’s Disease Pregnancies

To evaluate the predictive value of platelet activation and systemic inflammation indices for adverse perinatal and neonatal outcomes in pregnancies complicated by Behçet’s disease (BD). A retrospective matched case–control study was conducted including 50 pregnant women with BD and 70 healthy controls. First-trimester laboratory data were used to calculate platelet indices (MPV, PDW, PLCR) and systemic inflammation indices (SII, SIRI, AISI). Composite adverse perinatal outcomes (CAPO) were defined as the presence of ≥ 1 major neonatal complication. BD pregnancies had significantly lower MPV (10.4 vs. 10.8 fL, p = 0.007) and elevated PDW (13.3% vs. 11.2%, p < 0.001) and PLCR (30.8% vs. 26.6%, p < 0.001). Inflammatory indices were significantly higher in BD: AISI (579 vs. 423, p = 0.013), SII (843 vs. 694, p = 0.006), and SIRI (2.53 vs. 1.54, p = 0.021). Adverse outcomes were more frequent in BD, including higher rates of preterm birth (30.0% vs. 11.4%, p = 0.017), PPROM (10.0% vs. 1.4%, p = 0.011), FGR (12.0% vs. 1.4%, p = 0.020), and NICU admission (32.7% vs. 7.2%, p < 0.001). CAPO was significantly more prevalent in the BD group (36.0% vs. 15.7%, p = 0.019). ROC analysis showed PLCR (AUC = 0.764), PDW (AUC = 0.754), and SIRI (AUC = 0.647) as the most accurate predictors of CAPO. First-trimester platelet and systemic inflammation indices were significantly altered in pregnancies complicated by Behçet’s disease and were associated with composite adverse perinatal outcomes. Particularly, PDW and PLCR above the identified cut-offs predicted higher risk. These readily available hematological markers offer a novel, cost-effective approach for early risk stratification and may guide closer fetal growth surveillance and tailored antenatal care in BD pregnancies.