Purpose: To determine the diagnostic accuracy of insulin-like growth factor binding protein-1/alpha fetoprotein (Amnioquick duo+®) compared with traditional clinical assessment (TCA) of nitrazine, ferning and pooling for the diagnosis of prelabor rupture of membranes (PROM).
Methods: A double-blinded, multicenter clinical study was conducted between February 2015 and August 2015 among pregnant women presenting with symptoms or features suggestive of PROM between 24 and 42 weeks gestation. Confirmation of PROM was done after delivery based on the presence of any two of these criteria: delivery within 48 h to 7 days, evidence of chorioamnionitis, membranes explicitly ruptured at delivery and adverse perinatal outcomes strongly correlated with prolonged PROM. Sensitivity, specificity and accuracy were outcome measures assessed.
Results: Two hundred and thirty-six women were recruited. Three women were excluded from the final analysis due to lack of follow-up data and failure to meet inclusion criteria. Two hundred and thirty-three women had complete data for analysis. The specificity and sensitivity values for TCA were 76.2% and 85.2%, which were lower than those of Amnioquick duo+, which were 97.6% and 97.9%, respectively. The accuracy of Amnioquick duo+ was statistically higher (97.9% vs. 83.7%; RR=1.17; 95%CI=1.10-1.24; P<0.001). In equivocal cases (pooling=negative), the accuracy of Amnioquick duo+ vs. TCA was 98.4% vs. 69.4% (RR=1.42; 95%CI=1.20-1.68; P<0.001) at ≥34 weeks gestation and 100.0% vs. 71.4% (RR=1.40; 95%CI=1.07-1.83; P=0.021) at <34 weeks gestation.
Conclusion: The performance matrix of Amnioquick duo+® was superior to that of TCA for diagnosing PROM even in equivocal cases.