Placental α-microglobulin-1 to detect uncertain rupture of membranes in a European cohort of pregnancies

Purpose We evaluated the performance of the placental alpha-microglobulin-1 immunoassay (AmniSure (R), AT) in cervicovaginal secretions in patients with uncertain rupture of membranes (ROM) and investigated the influence of the examiners experience. Methods This prospective cohort study was performed in pregnant women (17-42 weeks of gestation) with signs of possible ROM. Evaluation included clinical assessment, examination for cervical leakage, Nitrazine test and measurement of the amniotic fluid index by ultrasound and AT. ROM occurrence was based on review of the medical records after delivery. Results 199 women were included. AT had a sensitivity of 94.4%; specificity of 98.6%; positive predictive value, 96.2%; negative predictive value, 98.0%. Clinical assessment showed a sensitivity of 72.2%; specificity of 97.8%; positive predictive value, 92.9%; negative predictive value, 90.6%. AT was more sensitive for diagnosing ROM (p = 0.00596) compared to clinical assessment, independent of the examiners experience. Furthermore, the sole use of AT reduced costs by 58.4% compared to clinical assessment. Conclusions AT was more sensitive compared to clinical assessment, independent of the examiners experience and gestational age. Our data extend its use in patients with uncertain ROM. Moreover, AT seems to be a cost-effective approach in the assessment of these patients.