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THE VALUE OF THE M6NP MODEL FOR PREDICTING ECTOPIC PREGNANCY IN PREGNANCIES OF UNKNOWN LOCATION AT HUNG VUONG HOSPITAL
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Abstract
Introduction: The management protocols for pregnancies of unknown location (PUL) in Vietnam remain inconsistent. The M6NP model has demonstrated good predictive performance for ectopic pregnancy (EP) in PUL cases across multiple studies but has not yet been applied in Vietnam. Objective: To evaluate the performance of the M6NP model in predicting ectopic pregnancy (EP) among women with pregnancies of unknown location (PUL). Methods: A diagnostic accuracy study was conducted using a retrospective cohort of 577 women with PUL from January 2022 to October 2024. Serum β-hCG levels were measured at the initial visit (T1) and after 48–72 hours (T2). The M6NP score was calculated based on the log-ratio of β-hCG T2/T1. Model performance was assessed using AUC, sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) at thresholds of 1.8%, 5%, and 17.4%. Results: The prevalence of EP was 31.2%. The AUC for the M6NP model was 0.8133. At the 5% threshold, Se was 81.7%, Sp 58.2%, and NPV 87.5%. At the 17.4% threshold (Youden’s index), Sp was 87.2% and PPV 70.5%. Conclusion: The M6NP model demonstrates good discriminatory ability for EP risk stratification (AUC > 0.80). A 5% threshold offers optimal safety, while a 17.4% threshold provides a balanced approach for resource utilization.
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Keywords
pregnancy of unknown location, ectopic pregnancy, M6NP, β-hCG
References
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