Introduction
Fetalfibronectin(fFN),anisoformoffibronectin,isnaturallyelevatedincervicovaginalsecretionsduringthefirst24weeksofpregnancy,butisdiminishedbetween24and34weeksinnormalpregnancies.DetectionoffFNincervicovaginalsecretionsbetween24and34completedweeksgestationisreportedtobeassociatedwithpretermdeliveryinsymptomatic3,4andasymptomaticpregnantwomen5,6.
PrincipleofthefFNRapidTestCassette
ThefFNRapidTestCassetteisavisuallyinterpreted,qualitativeimmunochromatographictestdeviceforthedetectionoffFNincervicovaginalsecretions,intendedasanaidtoassesstheriskofpre-termdeliveryduringpregnancy.Duringthetest,thespecimenisallowedtoreactwithcoloredanti-fFNantibodies.IffFNispresenceinthesampleabovedetectablelimits,acoloredbandwillformatthetestregionofthemembrane.Presenceofacoloredbandindicatesapositiveresult,whiletheabsenceofabandindicatesanegativeresult.Appearanceofacoloredbandatthecontrolregionservesasaproceduralcontrol.Presenceofthisbandindicatesthatpropervolumeofspecimenhasbeenaddedandmembranewickinghasoccurred.