The amnisure® ROM test is superior to conventional clinical assessment in the diagnosis of rupture of membranes

Abstract

MENT IN THE DIAGNOSIS OF RUPTURE OF MEMBRANES SI EUN LEE, JOONG SHIN PARK, ERROL NORWITZ, CHAN WOOK PARK, JONG KWAN JUN, HEE CHUL SYN, Seoul National University College of Medicine, Obstetrics & Gynecology, Seoul, South Korea, Yale University School of Medicine, Obstetrics, Gynecology & Reproductive Sciences, New Haven, Connecticut OBJECTIVE: The AmniSure ROM test is an immunoassay that measures levels of placental alpha-microglobulin-1 (PAMG-1) in cervicovaginal secretions. This study compares the accuracy of AmniSure ROM test with that of conventional clinical assessment for the diagnosis of rupture of membranes (ROM). STUDY DESIGN: A prospective observational study was performed involving consecutive patients presenting to Seoul National University Hospital with signs or symptoms of ROM from March 2005 to February 2006. Initial evaluation included both the standard clinical evaluation for ROM and the AmniSure ROM test. A diagnosis of ROM was made if fluid was seen leaking from the cervical os on speculum examination or if two of the following three clinical signs were present: visual pooling of fluid in the posterior fornix, positive nitrazine test, or microscopic evidence of ferning. A definitive clinical diagnosis of ROM was made on review of the medical records after delivery. Performance of the AmniSure ROM test was compared with that of the conventional clinical tests. RESULTS: Of the 184 patients (gestational age, 11 to 42 weeks) included in the analysis, a diagnosis of ROM at initial presentation was made in 76% (139/ 184) using conventional clinical assessment and 88% (161/184) using AmniSure ROM test. Subsequent review of the medical records confirmed that a total of 159 of 183 patients (87%) had ROM at their initial presentation. Using this longitudinal assessment as the clinical gold standard, AmniSure ROM test confirmed ROM at initial presentation with a sensitivity of 98.7% (157/ 159), specificity of 87.5% (21/24), positive predictive value of 98.1% (157/160), and negative predictive value of 91.3% (21/23). AmniSure ROM test was better than both the conventional clinical assessment and the nitrazine test alone in confirming the diagnosis of ROM. CONCLUSION: The AmniSure ROM test is superior to conventional clinical assessment in the diagnosis of ROM.