Diagnostic Accuracy of the Appendicitis Inflammatory Response (AIR) Score for Acute Appendicitis During Pregnancy: A Systematic Review and Diagnostic Meta-analysis

Purpose This diagnostic test accuracy meta-analysis evaluated the accuracy of the Appendicitis Inflammatory Response (AIR) score for acute appendicitis (AA) in pregnant women. Methods Following PRISMA guidance, PubMed, Embase, Scopus, and Web of Science were searched from inception through March 2026 for studies providing data to construct 2 × 2 contingency tables. Pooled sensitivity, specificity, and area under the curve (AUC) were estimated using a bivariate random-effects Reitsma model. Methodological quality was assessed using QUADAS-2. Meta-regression explored AIR cutoff, disease prevalence, and reference-standard category as potential sources of heterogeneity. Results Five studies met the eligibility criteria. The pooled sensitivity was 66.7% (95% CI: 44.2–83.5%) and specificity was 75.5% (95% CI: 40.0–93.5%), with a false-positive rate of 24.5% (95% CI: 6.5–60.0%). Overall diagnostic accuracy was moderate (AUC = 0.752; normalized pAUC = 0.669). Substantial heterogeneity was observed (Zhou–Dendukuri I² = 75.6%). AIR cutoff significantly moderated specificity (P < 0.001), but not sensitivity (P = 0.911). In a within-study analysis, increasing the cutoff from ≥4 to ≥9 reduced sensitivity from 99.1% to 36.8% and increased specificity from 42.4% to 97.0%. Conclusions The AIR score provides moderate accuracy for AA in pregnancy and should be used as an adjunct to clinical assessment rather than as a stand-alone diagnostic tool. Threshold selection contributes to variability in diagnostic performance. Prospective multicenter studies are needed to establish pregnancy-specific cutoffs.