Aim: The aim of this study was to compare the performance of tests based on the detection of insulin-like growth factor binding protein 1 (IGFBP-1) and placental α-microglobulin-1 (PAMG-1) in diagnosing rupture of fetal membranes (ROM) across different patient populations.
Methods: A meta-analysis was conducted on prospective observational or cohort studies investigating ROM tests based on the detection of IGFBP-1 and PAMG-1 meeting the following criteria: (1) performance metrics calculated by comparing results to an adequate reference method; (2) sensitivity thresholds of the investigated tests matching those of the currently available tests; (3) study population, as a minimum, included patients between 25 and 37 weeks of gestation. Sensitivities, specificities, and diagnostic odds ratios were calculated.
Results: Across all patient populations, the analyzed performance measures of the PAMG-1 test were significantly superior compared with those of the IGFBP-1 test. Of particular clinical relevance, PAMG-1 outperformed IGFBP-1 in the equivocal group, which comprised patients with uncertain rupture of membranes (sensitivity, 96.0% vs. 73.9%; specificity, 98.9% vs. 77.8%; PAMG-1 vs. IGFBP-1 tests, respectively).
Conclusions: Compared with its performance in women with known membrane status, the accuracy of the IGFBP-1 test decreases significantly when used on patients whose membrane status is unknown. In this latter clinically relevant population, the PAMG-1 test has higher accuracy than the IGFBP-1 test.