Effectiveness of Laboratory Parameters in Predicting Complicated Acute Appendicitis in Pregnant Patients: A Retrospective Analysis

Aim: Acute appendicitis during pregnancy presents a diagnostic challenge due to physiological and anatomical changes that can obscure classical symptoms.This study aimed to evaluate the predictive value of inflammatory markers-particularly C-reactive protein (CRP) and the CRP/albumin ratio (CAR)-for detecting complicated acute appendicitis in pregnant women.Method: This retrospective study included 67 pregnant patients who underwent appendectomy for acute appendicitis between October 2019 and December 2024.Patients were categorized into complicated and non-complicated appendicitis groups based on histopathological findings.Laboratory parameters comprising the platelet-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, neutrophil-to-lymphocyte ratio, systemic immune inflammation index, systemic inflammatory response index, receiver operating characteristic (ROC) curve, and decision curve analysis (DCA) were used to assess diagnostic and clinical performance.Results: Complicated appendicitis was identified in 25.4% (n=17) of patients.Multivariate regression demonstrated that CRP [odds ratio (OR)=1.095;95% confidence interval (CI)=1.042-1.151;p<0.001] and CAR (OR=23.863;95% CI=4.223-134.830;p<0.001) were independent predictors.The ROC analysis demonstrated high diagnostic accuracy for CRP [area under the curve (AUC)=0.954]and CAR (AUC=0.946).The DeLong test revealed no significant difference between CRP and CAR (p=0.878), and DCA confirmed that both markers provided higher net clinical benefit than "treat-all" or "treat-none" strategies. Conclusion:The results show that CRP and CAR may be promising, cost-effective biomarkers for early identification of complicated appendicitis in pregnancy, particularly where imaging is limited, but these single-center data require cautious interpretation and external validation before routine clinical use.