Diagnostic Accuracy of Transvaginal Ultrasonography and Serum β-hCG in the Diagnosis of Ectopic Pregnancy: A Systematic Review

Abstract

Ectopic pregnancy (EP) remains an important cause of first-trimester maternal death, and accurate early diagnosis depends heavily on transvaginal ultrasonography (TVS) and serum β-human chorionic gonadotropin (β-hCG), yet recent studies report conflicting figures on how accurate these tests really are, particularly when β-hCG is low. This review aimed to synthesize recent evidence (2020–2026) on the diagnostic accuracy of TVS and serum β-hCG, alone and combined, for diagnosing EP, searching PubMed, Google Scholar, and ScienceDirect for cross-sectional, cohort, and case-control studies verified against surgical, histopathological, or clinical follow-up reference standards, with quality appraised using QUADAS-2. Nine studies published between 2020 and 2026 met the inclusion criteria. TVS alone showed highly variable sensitivity, from as low as 15.8% in women with low β-hCG and subtle tubal signs to over 90% in symptomatic women with higher β-hCG, while its specificity remained consistently high, generally above 90%. Serum β-hCG alone performed moderately, with sensitivity around 81% and specificity around 75%, and combining TVS with β-hCG, and in some studies serum progesterone, consistently raised both sensitivity and specificity above 90%. Heterogeneity in reference standards and β-hCG cutoffs precluded formal statistical pooling, so findings are presented narratively. Neither TVS nor serum β-hCG alone is sufficiently accurate at low hormone concentrations, and combining both tests, ideally with serial measurement, remains the most reliable non-invasive strategy for diagnosing EP.