Evaluation of a novel placental alpha microglobulin-1 (PAMG-1) test to predict spontaneous preterm delivery

Abstract

Objective: The PartoSure™ time-to-delivery (TTD) test (AmniSure International, Boston, MA, USA) is a newly available bedside test for the prediction of time to spontaneous preterm delivery via the detection of placental alpha microglobulin-1. The objective of this study was to determine the efficacy of the test in predicting imminent delivery in 7 or 14 days from the time of testing. Methods: The study population consisted of 101 consecutively recruited pregnant women with singleton pregnancies between 20+0 and 36+6 weeks of gestation with symptoms of preterm labor, clinically intact amniotic membranes, and minimal cervical dilatation (≤3 cm). The PartoSure™ TTD test was performed on these patients and the test-to-spontaneous-delivery interval was calculated. Results: The PartoSure™ TTD test predicted spontaneous preterm delivery within 7 days with 90.0% sensitivity, 93.8% specificity, 97.4% negative predictive value (NPV), and 78.3% positive predictive value (PPV). The test predicted spontaneous preterm delivery within 14 days with 80% sensitivity, 96.1% specificity, 93.6% NPV, and 87.0% PPV. Conclusion: A positive PartoSure™ TTD test in patients presenting with symptoms of preterm labor, intact membranes, and minimal cervical dilatation (≤3 cm) indicated spontaneous preterm delivery will occur within 7 days with a high degree of accuracy. A negative result indicated that spontaneous preterm delivery within 14 days is highly unlikely.