Accuracy and response time of dual biomarker model of insulin‐like growth factor binding protein‐1/ alpha fetoprotein (Amnioquick duo+) in comparison to placental alpha‐microglobulin‐1 test in diagnosis of premature rupture of membranes

AIM: The aim of this study was to determine accuracy and response time of duo of insulin-like growth factor binding protein-1 (IGFBP-1)/alpha-fetoprotein (Amnioquick duo+) versus placental alpha-microglobulin-1 (PAMG-1) in diagnosing premature rupture of membranes (PROM). METHODS: A multicenter prospective study was conducted among women with features suggestive of PROM between 24 and 42 gestational weeks (GW). PROM was confirmed post-delivery based on presence of any two of these criteria: delivery within 48 h to 7 days, chorioamnionitis, membranes overtly ruptured at delivery, and adverse perinatal outcomes strongly correlated with prolonged PROM. Response time analysis was also done. Outcome measures included specificity, sensitivity, positive predictive value, negative predictive value, accuracy, and response time for both tests. RESULTS: Sensitivity, specificity, and accuracy for Amnioquick duo+ were 97.9%, 97.6%, and 97.9%, which were higher than the levels for PAMG-1, of 95.3%, 90.0%, and 95.7%, respectively (not significant). Accuracy of Amnioquick duo+ versus PAMG-1 in equivocal (pooling = negative) cases was (98.4% vs 96.8%) at ≥34 GW but each was 100.0% at <34 GW (not significant). Overall diagnostic concordance rate of Amnioquick duo+ and PAMG-1 was 97.0% and both have equal positive predictive value (99.5%). Response time analysis showed that the overall response time of PAMG-1 was 4.5% higher than that of Amnioquick duo+. CONCLUSION: This is the largest study to date to reveal that Amnioquick duo+ and PAMG-1 have a comparatively high diagnostic accuracy in identifying women with PROM, with a concordance rate of 97.0%. The diagnostic response time of Amnioquick duo+ appears shorter. In equivocal cases, accuracy of Amnioquick duo+ was equal to that of the PAMG-1.