Prospective evaluation of the efficacy of immunoassays in the diagnosis of rupture of the membranes

Abstract

Objective: To assess efficacy of immunoassays to diagnose spontaneous rupture of membranes (SROM).Study design: We performed a prospective, observational analysis comparing two immunoassays designed to diagnose SROM (rupture of membranes (ROM) Plus® and Amnisure®) to standard clinical assessment for SROM and 48 h follow-up. Subjects had a singleton pregnancy ≥15 weeks’ and suspected SROM. Sterile speculum exam (SSE) for nitrazine, ferning and pooling was performed. Immunoassays were run by independent providers blinded to results of SSE. The primary outcome was a final diagnosis of SROM at 48 h after initial evaluation.Results: Three hundred twenty-four subjects were enrolled (121 (37.3%) with SROM and 203 (62.7%) without SROM). Both ROM Plus® and Amnisure® had sensitivities and specificities >91% for the primary outcome. McNemar’s test revealed no significant difference between immunoassay test sensitivities and specificities.Conclusion: Both the ROM Plus® and Amnisure® immunoassays may be used to accurately diagnose SROM. Performance of the two immunoassays was statistically equivalent.