Objective: To compare the accuracy of a new combination monoclonal/polyclonal immunoassay point-of-care test with that of current conventional clinical assessment for diagnosis of ruptured amniotic membranes.
Study design: This was a multicenter prospective observational study performed in patients presenting with signs or symptoms of ruptured amniotic membranes. This clinical trial included 3 sites in the United States. Initial evaluation included both the standard clinical assessment for rupture of membranes (ROM) (speculum examination for fluid pooling, ferning, and nitrazine test), as well as the use of a new combination immunoassay test containing a combination monoclonal/polyclonal antibody approach to detect placental protein 12 (PP12) and alpha-fetoprotein (AFP). ROM was diagnosed if fluid was seen leaking from the cervical os, or if 2 of the 3 conditions were present: pooling of fluid, positive nitrazine test, or ferning. ROM was confirmed on review of the medical records following delivery.
Results: Of the 285 patients (15-42 weeks of gestation), the false positive rate for the new combination immunoassay test was 9% and the false negative rate was 0.5%, sensitivity 99%, specificity 91%, positive and negative predictive values of 95% and 99%, respectively. The conventional clinical evaluation's sensitivity was 85%, specificity 98%, with positive and negative predictive values of 99% and 77%. Ferning's sensitivity was 99%, specificity 72%, with positive and negative predictive values of 80% and 99%. Nitrazine testing's sensitivity was 93%, specificity 83%, with positive and negative predictive values of 90% and 88%.
Conclusion: This combination monoclonal and polyclonal immunoassay test that detects PP12 and AFP has an efficacy comparable to conventional testing and better than the individual components of conventional testing (ferning, nitrazine), is a quick and easy-to-use test that can be performed by a wider variety of care providers, and can improve triage and management of patients suspected of ROM.