The Role of Hemogram-Derived Inflammation Indices for the Prediction of Nausea and Vomiting in Pregnancy and the Need for Hospitalization

<b>Objective:</b> To investigate the association between inflammatory indices derived from complete blood count, including the systemic immune-inflammation index (SII), systemic inflammatory response index (SIRI), and pan-immune inflammation value (PIV), in predicting nausea and vomiting in pregnancy (NVP). <b>Methods:</b> Women diagnosed and treated for NVP at a tertiary care hospital between 2016 and 2021 were retrospectively analyzed. A total of 278 eligible patients with NVP and 278 gestational age-matched healthy pregnant women were included. Patients with NVP were categorized as having mild (<i>n</i> = 58), moderate (<i>n</i> = 140), or severe NVP (<i>n</i> = 80). Patients with moderate and severe NVP, who almost always required hospitalization, were grouped together and assigned to the inpatient treatment group. The groups were then compared. <b>Results:</b> SII and PIV were significantly higher in the NVP group than in the control group (<i>p</i> < 0.001 for both). In addition to SIRI, SII and PIV were also significantly higher in both the moderate NVP and HG groups compared to the mild NVP group (<i>p</i> = 0.017, 0.040, and 0.038, respectively, and <i>p</i> = 0.003, 0.009, and 0.006, respectively). SII, with a cut-off value of >966 × 10³/μL (63.67% sensitivity, 68.35% specificity), showed the best discriminatory performance for predicting NVP (<i>p</i> < 0.001), but there was no significant difference among SII, SIRI, and PIV in predicting the need for hospitalization. <b>Conclusions:</b> Our results show that there may be an association between high SII and PIV and an increased risk of developing NVP. In the future, after sufficient research, among these complete blood count-based inflammatory indices, SII may become an important component of regression models used as a screening tool to predict NVP, particularly in cases requiring inpatient care.