孕妇阴道流血的病因及诊治Word文档格式.docx
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DeputyEditor
VanessaABarss,MD
Disclosures
Alltopicsareupdatedasnewevidencebecomesavailableandourpeerreviewprocessiscomplete.
Literaturereviewcurrentthrough:
Mar2014.|Thistopiclastupdated:
一月6,2014.
INTRODUCTION
—
Vaginalbleedingisacommoneventatallstagesofpregnancy.Thesourceisvirtuallyalwaysmaternal,ratherthanfetal.Bleedingmayresultfromdisruptionofbloodvesselsinthedecidua(ie,pregnancyendometrium)orfromdiscretecervicalorvaginallesions.Thecliniciantypicallymakesaprovisionalclinicaldiagnosisbaseduponthepatient'
sgestationalageandthecharacterofherbleeding(lightorheavy,associatedwithpainorpainless,intermittentorconstant).Laboratoryandimagingtestsarethenusedtoconfirmorrevisetheinitialdiagnosis.
Anoverviewoftheetiologyandevaluationofvaginalbleedinginpregnantwomenwillbereviewedhere.Specificcausesofbleedingandtheirmanagementarediscussedindetailseparately.(Seeindividualtopicreviewsoneachsubject).
FIRSTTRIMESTERBLEEDING
Overview
Vaginalbleedingiscommoninthefirsttrimester,occurringin20to40percentofpregnantwomen.Itmaybeanycombinationoflightorheavy,intermittentorconstant,painlessorpainful.Thefourmajorsourcesofbleedinginearlypregnancyare:
●Ectopicpregnancy
●Miscarriage(threatened,inevitable,incomplete,complete)
●Implantationofthepregnancy
●Cervical,vaginal,oruterinepathology(eg,polyps,inflammation/infection,trophoblasticdisease)
Bleedingrelatedtomiscarriageisthemostcommoncauseoffirsttrimesterbleeding(prevalenceofmiscarriage15to20percentofpregnancies).Althoughbleedingmaybeheavy,onlyabout1percentofexpectantlymanagedwomenrequirebloodtransfusion[1].Ectopicpregnancyismuchlesscommon(prevalenceofectopicpregnancy:
2percentofpregnancies),butthemostseriousetiologyoffirsttrimesterbleedingasruptureoftheextrauterinepregnancyisalife-threateningcomplication;
therefore,thisdiagnosismustbeexcludedineverypregnantwomanwithbleeding.
Evaluation
Theexactetiologyofuterinebleedinginthefirsttrimesteroftencannotbedetermined;
thegoaloftheevaluationistomakeadefinitivediagnosiswhenpossibleandexcludethepresenceofseriouspathologyintheremainingcases(algorithm1).Ectopicpregnancyisparticularlyimportanttoexcludesinceitcanbelife-threatening.Thus,thefirststepinevaluationistodeterminewhetherthepatienthashadanultrasoundexamination,aswellastheresultsofthetest.Priordocumentationthatthepregnancyisinthenormalintrauterinelocationimmediatelynarrowsthedifferentialdiagnosis,althoughthepossibilitythatthepriorultrasoundmayhavemissedaheterotopicpregnancy(ie,oneintrauterineandoneextrauterinepregnancy)oracornual(interstitial)ectopicpregnancyshouldalwaysbeconsidered.Ifindoubt,considerhavinganexperiencedsonographerrepeattheultrasoundexamination.Itisalsoimportanttodeterminewhetherthepatientishemodynamicallyunstablesothatsupportivemeasuresandtreatmentcanberapidlyinitiated.
History
Theextentofbleedingshouldbedetermined:
isthewomanpassingbloodclotsoristhebloodsoakingthroughherclothes?
Doesshefeellightheaded?
Doesshehavesignificantpelvicpainorcramping?
Hasshepassedanytissue?
Ifsheanswersyestothesequestions,thenectopicpregnancyandmiscarriagearemuchmorelikelydiagnosesthanimplantationbleedingorcervicovaginaldisease(eg,polyps,cervicitis,cancer).Ontheotherhand,itisimportanttorememberthatthepresenceofonlylight,intermittent,painlessbleedingdoesnotexcludethepossibilityofalife-threateningunderlyingdisorder,suchasectopicpregnancy.
Whatisthepatient'
smedicalhistory?
Apasthistoryofectopicpregnancyorriskfactorsforectopicpregnancy(eg,historyofpelvicinflammatorydisease,presenceofanintrauterinecontraceptivedevice,adnexalsurgery)increasestheprobabilityofthisdisorder.(See"
Incidence,riskfactors,andpathologyofectopicpregnancy"
.)
Ahistoryoftwoormoreconsecutivemiscarriagesoraconditionassociatedwithmiscarriage(eg,parentalchromosomaltranslocation,maternalantiphospholipidsyndrome,uterineanomaly)suggestsbleedingmayberelatedtoimpendingpregnancyloss.(See"
Spontaneousabortion:
Riskfactors,etiology,clinicalmanifestations,anddiagnosticevaluation"
Useofassistedreproductivetechniquestoachieveconceptionincreasestheriskofheterotopicpregnancy.(See"
Abdominalpregnancy,cesareanscarpregnancy,andheterotopicpregnancy"
Physicalexamination
Orthostaticchangesinbloodpressureorpulseareindicativeofseverebloodlossrequiringsupportivecareandrapidtreatment.However,occasionally,youngpregnantwomencanhavemassivebleedingwithoutdemonstratingtachycardiaorhypotension.Careshouldbetakentoavoidunnecessarydelayinthemanagementofsuchpatients.
Anytissuethepatienthaspassedshouldbeexamined.Patientsmaymistakebloodclotfortheproductsofconception.Ifthetissuerepresentsapartialorcompletemiscarriage,thefetalmembranes,frondsindicativeofplacentalvilli,oranintactfetusshouldbevisibleuponcarefulexamination.Visualizationofvillicanbefacilitatedbyfloatingtheproductsofconceptioninwater(picture1A-B).
Thepatient'
sabdomenshouldbeexaminedbeforeperforminganinternalexamination.Itisbesttobeginbyexaminingthequadrantwherethepatientisexperiencingtheleastpain.Gentlepercussionispreferredtodeeppalpationsinceitcauseslesspainandguarding.Midlinepainismoreconsistentwithmiscarriage,whilelateralpainismoreconsistentwithectopicpregnancy.Nongynecologiccausesofpainarealsotobeconsidered.(See"
Approachtoabdominalpainandtheacuteabdomeninpregnantandpostpartumwomen"
Theclinicianshoulddeterminewhetheruterinesizeisappropriatefortheestimatedgestationalage.Thesize-gestationalagecorrelationislearnedbyexperienceandisoftendescribedintermsoffruit(eg,6-to8-weeksize=smallpear,8-to10-weeksize=orange,10-to12-weeksize=grapefruit).Theuterusremainsapelvicorganuntilapproximately12weeksofgestation,whenitbecomessufficientlylargetopalpatetransabdominallyjustabovethesymphysispubis.Thenormaluterusisnontender,smooth,andfirm.
Ifthepregnancyisatorbeyond10to12weeksofgestation,ahandheldDopplerdevicecanbeusedtocheckthefetalheartbeat.Thefetalheartrateusuallycanbeeasilydistinguishedfromthematernalheartratesincethefetalheartrateistypicallyintherangeof110to160beatsperminute;
however,thedifferenceinmaternalandfetalheartratescanbeminimalifthemotherhastachycardia[2].Dopplerconfirmationoffetalcardiacactivityisreassuring,asitindicatesbleedingisnotrelatedtofetaldemiseandunlikelytoberelatedtoanectopicpregnancy.Ontheotherhand,lossofapreviouslydetectedfetalheartbeatshouldraisesuspicionthatfetaldemisehasoccurred.However,inabilitytodetectfetalheartmotionbyDoppler,particularlyinthefirsttrimester,maymerelyreflectthedifficultyinblindlyfindingthelocationofthetinyfetalheart.
Aftertheabdominalexamination,thepatientisplacedinthelithotomyposition.Theexternalgenitaliaareexaminedtoassessthevolumeandsourceofbleedingandthenaspeculumisinsertedintothevagina.Ifbloodclots,productsofconception,orbotharepresent,theycanberemovedwithgauzespongesonaspongeforceps.Thistissueisexaminedasdescribedaboveand,byconvention,sentforpathologicexaminationtoconfirmthepresenceofproductsofconceptionandtoexcludegestationaltrophoblasticdisease.Theutilityofroutinehistopathologicalexaminationisquestionable,asitrarelysuggeststheunderlyingcauseofthepregnancyfailureorestablishesadiagnosisofgestationaltrophoblasticdisease[3].However,pathologistscansometimesdiagnoseentitiesthataretheprobablecauseofthelossorassociatedwithrecurrence.Theseincludemassivechronicintervillositis,massiveintervillousfibrindeposition,maternalvasculitis,findingssuggestiveofsomechromosomalanomalies(eg,triploidy,sometrisomies),andsepticabortion.
Speculumexaminationmayrevealasourceofbleedingunrelatedtopregnancy;
insuchcases,furtherevaluationdependsuponthenatureoftheabnormality:
●Vaginallaceration(see"
Evaluationandmanagementoflowergenitaltracttraumainwomen"
)
●Vaginalneoplasm(see"
Vaginalcancer"
●Vaginalwarts(see"
Condylomataacuminata(anogenitalwarts)"
●Vaginaldischarge(see"
Approachtowomenwithsymptomsofvaginitis"
●Cervicalpolyps,fibroids,ectropion(see"
Congenitalcervicalanomaliesandbenigncervicallesions"
●Mucopurulentcervicaldischargeorfriabilityattheendocervicalos(see"
Acutecervicitis"
●Cervicalneoplasm(see"
Invasivecervicalcancer:
Epidemiology,riskfactors,clinicalmanifestations,anddiagnosis"
Visualizationofthecervicaloshelpstodistinguishbetweenathreatenedandanimpending/inevitablemiscarriage.Directvisualizationofthegestationalsacinadilatedcervixisgenerallysufficienttodiagnoseanimpending/inevitablemiscarriageclinically.Thecervixwillusuallyalsobeopenwithanincompleteorarecentcompletemiscarriage.Anopeninternalcervicaloswilladmitasmallinstrument,suchasacotton-tippedswab.Ultrasoundcanprovideadditionalinformationinthesecases,suchasw