AmniSure Placental Alpha Microglobulin-1 Rapid Immunoassay for Detection of Rupture of Membranes: A Comparison Study With Clinical-Based Testing

Abstract

The timely and accurate diagnosis of rupture of fetal membranes (ROM) is crucial because it may be associated with serious neonatal and maternal consequences. Failure to identify patients with ROM, premature ROM, or preterm premature ROM may lead to infection, oligohydramnios, preterm delivery, fetal distress, prolapsed cord, and abruptio placenta. AmniSure ROM Test (AmniSure International, Cambridge, MA) is a rapid, qualitative immunochromatographic assay for the in vitro detection of PAMG-1 (placental alpha microglobulin-1) protein in vaginal swabs. This test was compared with the current diagnostic methods of nitrazine/pH test, microscopic fern test, and assessment of amniotic fluid pooling.Vaginal swab specimens from 25 pregnant women triaged at Danbury Hospital's Labor and Delivery Unit were collected from October 6, 2010 to January 26, 2011.IRB approval was obtained.Participants who consented had the standard clinical examination and the AmniSure test performed. Physicians were blinded to the results of the AmniSure test. Performance metrics were calculated vs the final determination of ROM following clinical record (chart) review. Our final analysis shows that the AmniSure test was more sensitive than the nitrazine and microscopic fern tests. The AmniSure test was more specific than the nitrazine test.The AmniSure and microscopic fern tests showed 100% specificity. The AmniSure test was more accurate in diagnosing ROM than the nitrazine and microscopic fern tests. The AmniSure ROM placental alpha microglobulin-1 test is highly predictive of rupture of fetal membranes and provides results that exceed the sensitivity, accuracy, and negative predictive value of the currently available methods (nitrazine and fern tests). It is a noninvasive, rapid test that will aid health care professionals in the detection of rupture of fetal membranes in pregnant women who report signs, symptoms or complaints suggestive of ROM.