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NewZealandObstetricDopplerGuideline,NZMFMN,revisedOctober2015,Page1
NEWZEALANDOBSTETRICDOPPLERGUIDELINE
ThisisaNewZealandguidelinefortheperformanceofobstetricDopplerexaminations.TheguidelineincorporatesdetailednotesoncorrectDopplertechnique,interpretationandreferencechartsforeachofcommonlyusedobstetricDopplerexaminations.Allhealthpractitionersinvolvedintheperformanceandinterpretationofobstetricultrasoundexaminationsareencouragedtousethisdocumentandincorporatetheprinciplesandreferencevaluesintotheirclinicalpractice.
Unalteredcopiesofthisguidelinemaybefreelyreproducedanddistributed.
Contributors:MartinNecas,DrEmmaParry,ProfessorLesleyMcCowan
NewZealandObstetricDopplerGuideline,NZMFMN,revisedOctober2015,Page2
WhichDopplerTestWhen?
SGAorIUGR UmbilicalarteryPI +
MeanuterinearteryPIattimeofdiagnossi(once)
UmbilicalarteryPIraised AddMCAPI+CPR Samedayreferraltospecialist
AddMCAPI+CPR Specialistreviewnow
Absentorreversedend-diastolicflow
Normal>34weeks AddMCAPI+CPR
Normal<34weeks Specialistreviewin1-2weeks
AtriskofearlyonsetmaternalhypertensivedisorderorSGA
MeanuterinearteryPIat20or24weeks
Suspectedfetalanaemia MCAPSV
MCDATwins NoevidenceofTTTS Bothtwins: UAPIfrom16weeks+MCAPSVfrom24weeks
Bothtwins: UAPI,MCAPI,MCAPSV,DVPI TTTS
NewZealandObstetricDopplerGuideline,NZMFMN,revisedOctober2015,Page3
UmbilicalArteryPulsatilityIndex(UAPI)Indications:
§ Suspectedorknownsmallforgestationalage(SGA)fetus§ TheestimatedfetalweightontheGROWchartis<10thpercentile§ TheestimatedfetalweightontheGROWchartisdroppingpercentilesby≥30%§ Theabdominalcircumferenceonthepopulationscanchartis<5thpercentile§ Discrepancy(≥30%)betweentheheadandabdominalcircumferencepercentilewithlowerACpercentile§ Maternalhypertensivedisorderse.g.preeclampsia§ Decreasedfetalmovements
Notindicated:§ Routinescreeningofnormalpregnancieswithnomaternalorfetalriskfactors
Howtoperformthetest:§ Performassessmentduringfetalquiescence§ AlwayskeepTIb<0.5ifpossibleoratleast<1byreducingtheacousticoutputpower§ IdentifyafreeloopofumbilicalcordoncolourDoppler§ UsehighcolourPRFtoavoidaliasingandconservativegaintoavoidcolourbleeding§ PositionthesamplevolumeinaportionofthecordcoursingparalleltoDopplerbeam§ AvoidsamplinginsuchawaythattheDopplerbeamisdirectedtowardsfetaleyes§ OptimisethespectralDopplerbaseline,PRFandsweepspeedtogetalargewaveform§ IftheEDVisnearthebaseline,ensurewallfilterissufficientlylowtodisplayEDV§ IfthePIiswithinnormalrange,onlysampleoneoftheumbilicalarteries§ IfthePIisabnormal,samplebothumbilicalarteriesandusethemorenormal(lower)value§ Iftheend-diastolicflowisabsentorreversed,commentonthisfindinginthereport
Howtointerpretthetest:§ >95thpercentileisabnormal
Commonpitfalls:§ PoorDopplerangleandpooroptimisationleadingtofuzzywaveformwhichishardtomeasure§ End-diastolicflowisnotvisualisedduetohighfiltersetting§ End-diastoleisnotwellvisualisedwhenEDVisnearbaselinebecauseofvenouscontamination-
readjustsamplingtoavoidcapturingadjacentUV
Reference:Ebbing,C.,Rasmussen,S.,&Kiserud,T.Middlecerebralarterybloodflowvelocitiesandpulsatilityindexandthecerebroplacentalpulsatilityratio:longitudinalreferencerangesandtermsforserialmeasurements.UltrasoundObstetGynecol,2007.30(3):p.287-96.
NewZealandObstetricDopplerGuideline,NZMFMN,revisedOctober2015,Page4
MiddleCerebralArteryPulsatilityIndex(MCAPI)Indications:
§ SGAwithabnormalUAPIatanygestationalage§ SGAwithnormalUAPIafter34weeksgestationalage§ MCDAtwingestationwithTTTS
Howtoperformthetest:
§ Performassessmentduringfetalquiescence§ AlwayskeepTIb<0.5ifpossibleoratleast<1byreducingtheacousticoutputpower§ StartwiththeBPDview§ Movecaudallytovisualisethebutterflyshapeofsuprasellarcisternsandthesphenoid§ Usethecoronalsuture/sphenoidalfontanelleasanacousticwindow§ Usehighdefinition(write)zoom§ ActivatecolourDopplertovisualisetheMCA§ AssesstheMCAwhichisclosertothetransducer§ MoveanteriorlyandanglebacktoaligntheMCAflowdirectionwiththeDopplerbeam§ Positionasmall(0.5-1mm)samplevolume2mmbeyondfromtheMCAorigin§ OptimisethespectralDopplerbaselineandPRFtogetalargewaveform
Howtointerpretthetest:
§ <5thpercentileisabnormal
Commonpitfalls:
§ PoorDopplerangleandpooroptimisationleadingtofuzzywaveformwhichishardtomeasure§ GatetooclosetoMCAoriginwheremultidirectionalcontaminationfromACAandPCoAoccurs§ SamplepositionedtooperipherallyintheMCAwherevelocitiesfall§ PCAmisidentifiedasMCA§ Poorvisualisationduetoinadequatezoom
Reference:Ebbing,C.,Rasmussen,S.,&Kiserud,T.Middlecerebralarterybloodflowvelocitiesandpulsatilityindexandthecerebroplacentalpulsatilityratio:longitudinalreferencerangesandtermsforserialmeasurements.UltrasoundObstetGynecol,2007.30(3):p.287-96.
NewZealandObstetricDopplerGuideline,NZMFMN,revisedOctober2015,Page5
CerebroplacentalRatio(CPR)Indications:
§ IfMCAPIassessmentwasperformed,theCPRshouldbecalculatedandrecorded
HowtocalculateCPR:
§ TheCPRisdefinedtheratioofMCAPIandUAPI
Howtointerpretthetest:
§ <5thpercentileisabnormal§ Note:ItcanbehelpfultoplottheMCAandCPRresultsonserialassessmentsto
determinethetrend
Reference:Ebbing,C.,Rasmussen,S.,&Kiserud,T.Middlecerebralarterybloodflowvelocitiesandpulsatilityindexandthecerebroplacentalpulsatilityratio:longitudinalreferencerangesandtermsforserialmeasurements.UltrasoundObstetGynecol,2007.30(3):p.287-96.
NewZealandObstetricDopplerGuideline,NZMFMN,revisedOctober2015,Page6
DuctusVenosusPulsatilityIndex(DVPI)Indications:
§ MarkedlyraisedUAPI(>>95th)andreducedMCAPIinpretermSGA§ MCDAtwingestationwithTTTSorselectiveIUGR
Howtoperformthetest:
§ Performassessmentduringfetalquiescence§ AlwayskeepTIb<0.5ifpossibleoratleast<1byreducingtheacousticoutputpower§ SagittalandtransverseapproachesareacceptableaslongasDopplerangleis0-60degrees§ ActivatecolourDopplertoidentifyDVattheendofUV§ Enlargetheimage§ 0.5-1mmgateplacedintheinletofDV§ Setwallfilterlow,sweepspeedhigh§ OptimisethespectralDopplerbaselineandPRFtogetalargewaveform§ IfPI>95thpercentile,assessumbilicalveinforpulsatility
Howtointerpretthetest:
§ >95thpercentileisabnormal
CommonPitfalls
§ ColourPRFtoolowandgaintoohighleadingtodifficultyinDVidentificationamongstothervessels§ Samplesizetoolarge,leadingtocontaminationfromothervessels§ SamplenotplacedattheinletoftheDV§ AdjacenthepaticveinorceliacaxismisidentifiedasDV§ PoorDopplerangleandpooroptimisationleadingtofuzzywaveformwhichishardtomeasure§ FetalbreathingactivitymayresultinfalseimpressionofabsentAwave
Reference:Kessler,J.,Rasmussen,S.,Hnson,M.,&Kiserud,T.Longitudinalreferencerangesforductusvenosusflowvelocitiesandwaveformindices.UltrasoundObstetGynecol,2006.28:890-898.
NewZealandObstetricDopplerGuideline,NZMFMN,revisedOctober2015,Page7
MCAPeakSystolicVelocity(MCAPSV)Indications:
§ Maternal-fetalisoimmunisation§ Anysuspicionoffetalanaemia§ Unexplainedhydrops§ MCDAtwins>24weeksgestationalage§ MCDAtwinswithknownorsuspectedofTTTSorTAPS
Howtodoperformthetest:
§ Performassessmentduringfetalquiescence§ AlwayskeepTIb<0.5ifpossibleoratleast<1byreducingtheacousticoutputpowerwhenrequired§ StartwiththeBPDview§ Movecaudallytovisualisethebutterflyshapeofsuprasellarcisternsandthesphenoid§ Usethecoronalsuture/sphenoidalfontanelleasanacousticwindow§ Usehighdefinition(write)zoom§ ActivatecolourDopplertovisualisetheMCAandassesstheMCAwhichisclosertothetransducer§ MoveanteriorlyandanglebacktoaligntheMCAflowdirectionwiththeDopplerbeam§ Idealinterrogationangleis0degreesbut30degreesorlessisacceptable§ Positionasmall(0.5-1mm)samplevolume2mmbeyondfromtheMCAorigin§ OptimisethespectralDopplerbaselineandPRFtogetalargewaveform§ IftheDopplerangleisnotzero,anglecorrectionmustbeused§ IfPSV>1.5multiplesofthemedian(MoM),obtain3highqualitysamplesandusethehighestvalue
Howtointerpretthetest:
§ >1.5MoMisabnormal
CommonPitfalls:
§ PoorDopplerangleandpooroptimisationleadingtofuzzywaveformwhichishardtomeasure§ GatetooclosetoMCAoriginwheremultidirectionalcontaminationfromACAandPCoAoccurs§ SamplepositionedtooperipherallyintheMCAwherevelocitiesfall§ PCAmisidentifiedasMCA§ Failuretoangle-correctatanglesotherthan0leadingtounderestimationofPSV§ Poorvisualisationduetoinadequatezoom References:
Mari,G.NoninvasiveDiagnosisbyDopplerultrasonographyoffetalanemiaduetomaternalred-cellalloimmunization.NEnglJMed2000;342:9-14,p9-14.Mari,G.Middlecerebralarterypeaksystolicvelocityforthediagnosisoffetalanemia:theuntoldstory.UltrasoundObstetGynecol2005Apr;25(4):323-30.
NewZealandObstetricDopplerGuideline,NZMFMN,revisedOctober2015,Page8
MeanuterineArteryPulsatilityIndexIndications:
§ ScreenpatientsathighriskofearlypreeclampsiaorearlySGAat20or24weeks§ Ifabnormalat20weeks,repeatat24weeks§ EarlyonsetIUGR§ Currenthypertensivedisorderinpregnancy§ FullassessmentofsuspectedSGApregnancy
Howtoperformthetest:
§ Locatethematernalanteriorsuperioriliacspineandanglemedially§ Alternativelyvisualizetheexternaliliacartery(EIA)§ TheuterinearteryistypicallyseencrossingtheEIAanteriorly§ SelectaportionoftheuterinearterywhichcoursesatafavourableDopplerangle0-60degrees§ OptimisethespectralDopplerbaselineandPRFtogetalargewaveform§ MeasuretherightandleftPIandcalculatethemeanvalue
Howtointerpretthetest:
§ >95thpercentileisabnormal§ Bilateralnotchingafter24weeksisabnormal
CommonPitfalls:
§ Failuretoidentifytheuterinearterybynotscanninginferiorlyenough
Reference:GomezO.,etal.Referencerangesforuterinemeanpulsatilityindexat11-41weeksofgestation.UltrasoundObstetGynecol2008;32:128-132.
NewZealandObstetricDopplerGuideline,NZMFMN,revisedOctober2015,Page9
QuickReferenceTables
UmbilicalArteryPIv MCAPIv
CerebroplacentalRatio(CPR)v
MeanUterineArteryPIö
CPR=MCAPI/UAPI MeanPI=(RTPI+LTPI)/2 >95thpercentileisabnormal <5thpercentileisabnormal <5thpercentileisabnormal >95thpercentileisabnormal
GestationWeeks
50thpercentile
95thpercentile
50thpercentile
5thpercentile
50thpercentile
5thpercentile
50thpercentile
95thpercentile
18 1.20 1.7919 1.25Ô 1.63Ô 1.15 1.7020 1.22Ô 1.59Ô 1.10 1.6121 1.15 1.46 1.05 1.5422 1.13 1.43 1.00 1.4723 1.10 1.40 0.96 1.4124 1.08 1.38 1.86 1.38 1.74 1.16 0.93 1.3525 1.06 1.35 1.94 1.44 1.85 1.24 0.89 1.3026 1.04 1.33 2.01 1.50 1.95 1.32 0.86 1.2527 1.02 1.31 2.06 1.55 2.05 1.40 0.84 1.2128 1.00 1.28 2.11 1.58 2.14 1.47 0.81 1.1729 0.98 1.26 2.15 1.61 2.21 1.53 0.79 1.1330 0.96 1.24 2.16 1.62 2.28 1.58 0.77 1.1031 0.94 1.21 2.16 1.62 2.32 1.62 0.75 1.0632 0.92 1.19 2.14 1.61 2.35 1.64 0.73 1.0433 0.90 1.16 2.10 1.58 2.36 1.65 0.71 1.0134 0.88 1.14 2.04 1.53 2.35 1.63 0.70 0.9935 0.86 1.11 1.96 1.47 2.32 1.60 0.69 0.9736 0.84 1.09 1.86 1.39 2.27 1.55 0.68 0.9537 0.81 1.06 1.75 1.30 2.19 1.48 0.67 0.9438 0.79 1.03 1.63 1.20 2.09 1.40 0.66 0.9239 0.77 1.00 1.49 1.10 1.97 1.29 0.65 0.9140 0.75Ô 1.07Ô 1.29ø 1.02ø 1.80ø 1.24ø 0.65 0.90
References:ÔAcharyaG,etal.Referencerangesforserialmeasurementsofbloodvelocityandpulsatilityindexattheintra-abdominalportion,andfetalandplacentalendsofumbilicalartery.UltrasoundObstetGynecol2005;26:162-169. v Ebbing,C.,Rasmussen,S.,&Kiserud,T.Middlecerebralarterybloodflowvelocitiesandpulsatilityindexandthecerebroplacentalpulsatilityratio:longitudinalreferencerangesandtermsforserialmeasurements.UltrasoundObstetGynecol,2007.30(3):p.287-96.øBaschatAA,GembruchU.ThecerebroplacentalDopplerratiorevisited.UltrasoundObstetGynecol2003;21:124-127.ö GomezO,etal.Referencerangesforuterinemeanpulsatilityindexat11-41weeksofgestation.UltrasoundObstetGynecol2008;32:128-132.
NewZealandObstetricDopplerGuideline,NZMFMN,revisedOctober2015,Page10
ObstetricDopplerreferencecharts
NewZealandObstetricDopplerGuideline,NZMFMN,revisedOctober2015,Page11
Reference:Ebbing,C.,Rasmussen,S.,&Kiserud,T.Middlecerebralarterybloodflowvelocitiesandpulsatilityindexandthecerebroplacentalpulsatilityratio:longitudinalreferencerangesandtermsforserialmeasurements.UltrasoundObstetGynecol,2007.30(3):p.287-96.
NewZealandObstetricDopplerGuideline,NZMFMN,revisedOctober2015,Page12
Reference:Ebbing,C.,Rasmussen,S.,&Kiserud,T.Middlecerebralarterybloodflowvelocitiesandpulsatilityindexandthecerebroplacentalpulsatility:longitudinalreferencerangesandtermsforserialmeasurements.UltrasoundObstetGynecol,2007.30(3):p.287-96.
NewZealandObstetricDopplerGuideline,NZMFMN,revisedOctober2015,Page13
Reference:Ebbing,C.,Rasmussen,S.,&Kiserud,T.Middlecerebralarterybloodflowvelocitiesandpulsatilityindexandthecerebroplacentalpulsatiliyratio:longitudinalreferencerangesandtermsforserialmeasurements.UltrasoundObstetGynecol,2007.30(3):p.287-96.
NewZealandObstetricDopplerGuideline,NZMFMN,revisedOctober2015,Page14
Reference:GomezO.,etal.Referencerangesforuterinemeanpulsatilityindexat11-41weeksofgestation.UltrasoundObstetGynecol2008;32:128-132.
NewZealandObstetricDopplerGuideline,NZMFMN,revisedOctober2015,Page15
Reference:Kessler,J.,Rasmussen,S.,Hnson,M.,&Kiserud,T.Longitudinalreferencerangesforductusvenosusflowvelocitiesandwaveformindices.UltrasoundObstetGynecol,2006.28:890-898.
NewZealandObstetricDopplerGuideline,NZMFMN,revisedOctober2015,Page16
References:Mari,G.NoninvasiveDiagnosisbyDopplerultrasonographyoffetalanemiaduetomaternalred-cellalloimmunization.NEnglJMed2000;342:9-14,p9-14.
Mari,G.Middlecerebralarterypeaksystolicvelocityforthediagnosisoffetalanemia:theuntoldstory.UltrasoundObstetGynecol2005Apr;25(4):323-30.