examination and assessment of the neonate：新生儿的检查和评估

Chapter5ExaminationandAssessmentoftheNeonateGestationalAgeandSizeGAassessmentshouldbedonewithin12hoursoflifeforbestreliabilityforinfantslessthan26weeksEvaluationoftheinfantisbasedonthreebasicelements:GestationalageMaternalmenstrualcyclePrenatalultrasoundPostnatalassessment(BallardScore)EstimatingtheDeliveryDate

Nagele’sRulea.

Threemonthsaresubtractedfromthefirstdayofthelastmenstrualperiod,thensevendaysareaddedtotheresultb.

Forexample,ifthefirstdayofthelastmenstrualperiodisMay15,subtracting3monthswouldarriveatFebruary15.

Adding7daysgivesanEDCasFebruary22c.

Requiresaregularcycleof28days,useoforalcontraceptivesorirregularcyclereducestheaccuracyEstimatingtheDeliveryDate

FundalHeighta.

Fundusistheportionoftheuterusoppositethecervixb.

Thedistancefromthesymphysispubisandthetopofthefundusismeasuredc.

Thedistanceincentimetersisequaltothegestationalage(20cm=20weeks)d.

CorrelatesduringthefirsttwotrimestersEstimatingtheDeliveryDate

Quickeninga.

Sensationoffetalmovementb.

Usuallyoccursat16-22weeksc.

VeryroughestimateofgestationalageDeterminationofFetalHeartbeata.

Thefetalheartbeatisheardbetween16-20weeksgestationb.

Asearlyas8weekswithaDopplerdevicec.

RoughestimateofgestationagePrenatalAssessmentsBiophysicalTestsofWellBeing

Contractionstresstest(CST)a.

CSTassessesfetalresponsetocontractionsb.

Determinesthepresenceofuteroplacentalinsufficiencyc.

Fetusisstressedduringcontractionsd.

PositiveCST:50%ofcontractionshaveTypeIIFHRdecelerationse.

NegativeCST:nodecelerationinFHRf.

Mosttestsfallsomewhereinbetweeng.

CanfetustoleratenormallaboranddeliveryorisCesariansectionneeded?BiophysicalTestsofWellBeing

Contractionstresstest(CST)VariationofCST:OxytocinContractionTest(OST)IVisusedtostartcontractionsPositiveCSTindicatesinductionfordeliveryBiophysicalTestsofWellBeing

TheNon-StressTest(NST)a.

TheresponseofFHRtomovementisobservedb.

FHRincreases15bpm>baselineforatlest15secondsc.

PositiveNST:atleast2accelerationsovera20minuteperiodd.

NegativeNST:noaccelerationsovera20minuteperiode.

Fetalmonitorisplacedonmom’sabdomen;Mompressesabuttonwhenthebabymovesf.

Simpletoperform,lesstimeconsuming,littleriskBiophysicalTestsofWellBeingInterpretationofCSTandNSTPositiveCSTandNegativeNST1.

FetuswithhypoxiaNegativeCSTandNegativeNST1.

Fetalsleep2.

CNSdepressionBiophysicalTestsofWellBeingAcousticStimulationa.

Buzzeragainstmom’sabdomenb.

FHRmonitoredforaccelerationsc.

Failuretoaccelerateindicatesthatthefetusiscompromisedandfurthertestingisrequired

TheBiophysicalProfilea.

Fetalbreathingb.

Fetalmovementc.

Fetallimbtoned.

NSTe.

Amnioticfluidvolumef.

Normalscoreis8-10g.

MaybebestoverallmethodoffetalriskdeterminationChorionicvillussamplingFormofprenataldiagnosistodeterminechromosomalorgeneticdisordersinthefetus.Itentailssamplingofthechorionicvillus(placentaltissue)andtestingitforchromosomalabnormalities,usuallywithFISH(fluorescenceinsituhybridization)orpolymerasechainreaction(PCR)CVSusuallytakesplaceat10–12weeks'gestation,earlierthanamniocentesisorpercutaneousumbilicalcordbloodsampling.Itisthepreferredtechniquebefore15weeksPossiblereasonsforhavingaCVScaninclude:

AbnormalfirsttrimesterscreenresultsIncreasednuchaltranslucencyorotherabnormalultrasoundfindingsFamilyhistoryofachromosomalabnormalityorothergeneticdisorderParentsareknowncarriersforageneticdisorderAdvancedmaternalage(maternalageabove35).AMAisassociatedwithincreaseriskofDown'ssyndromeandatage35,riskis1:400.

ScreeningtestareusuallycarriedoutfirstbeforedecidingifCVSshouldbedone.Amniocentesisusedinprenataldiagnosisofchromosomalabnormalitiesandfetalinfectionsasmallamountofamnioticfluid,whichcontainsfetaltissues,issampledfromtheamnionoramnioticsacsurroundingadevelopingfetus,andthefetalDNAisexaminedforgeneticabnormalities.AmniocentesistestsL/SRatioandpresenceofPGAlpha-Fetoprotein(AFP):increasedinneuraltubedefects,decreasedinDown’sSyndromeandinfetaldeathBilirubin:hemolyticdiseasesuchasRhincompatibilityCreatinineLevels:determinefetalkidneymaturityMeconiumStaining:greenfluid(normallyclear)Cytology:cellsfromskin,amnion,TBtree,detectgeneticandchromosomaldisorders;culturedandgrown;takestwoweeksforresultsAmniocentesisAmniocentesiscanalsobeusedtodetectproblemssuchas:Infection,inwhichamniocentesiscandetectadecreasedglucoselevel,aGramstainshowingbacteriaoranabnormaldifferentialcountofwhitebloodcellsRhincompatibilityDecompressionofpolyhydramniosGeneticdiagnosis

Earlyinpregnancy,amniocentesisusedfordiagnosisofchromosomalandotherfetalproblemssuchas:Downsyndrome(trisomy21)Trisomy13Trisomy18FragileXRare,inheritedmetabolicdisordersNeuraltubedefects(anencephalyandspinabifida)byalpha-fetoproteinlevels.Trisomy13(PatauSyndrome)Someorallofthecellsofthebodycontainextrageneticmaterialfromchromosome13.Fulltrisomy13iscausedbynondisjunctionofchromosomesduringmeiosis(themosaicformiscausedbynondisjunctionduringmitosis)Disruptsthenormalcourseofdevelopment,causingsevereheartandkidneydefectsriskofthissyndromeintheoffspringincreaseswithmaternalageatpregnancy,withabout31yearsbeingtheaverage.[Patausyndromeaffectssomewherebetween1in10,000and1in21,700livebirthsTrisomy18(EdwardsSyndrome)Presenceofallorpartofanextra18thchromosome.Thisgeneticconditionalmostalwaysresultsfromnondisjunctionduringmeiosis.Itisthesecondmostcommonautosomaltrisomy,afterDown'ssyndrome,thatcarriestoterm.Edwardssyndromeoccursinaroundonein6,000livebirthsandaround80percentofthoseaffectedarefemale.Themajorityoffetuseswiththesyndromediebeforebirth.Theincidenceincreasesasthemother'sageincreases.Thesyndromehasaverylowrateofsurvival,resultingfromheartabnormalities,kidneymalformations,andotherinternalorgandisorders.FragileXsyndrome(FXS),Martin–Bellsyndrome,orEscalante'ssyndromegeneticsyndromethatisthemostwidespreadsingle-genecauseofautismandinheritedcauseofmentalretardationamongboys.Itresultsinaspectrumofintellectualdisabilitiesrangingfrommildtosevereaswellasphysicalcharacteristicssuchasanelongatedface,largeorprotrudingears,andlargetestes(macroorchidism),andbehavioralcharacteristicssuchasstereotypicmovements(e.g.hand-flapping),andsocialanxiety.Amniocentesisandlungmaturityfetallungmaturity,whichisinverselycorrelatedtotheriskofinfantrespiratorydistresssyndrome.Inpregnanciesofgreaterthan30weeks,thefetallungmaturitymaybetestedbysamplingtheamountofsurfactantintheamnioticfluid.lecithin-sphingomyelinratio("L/Sratio"),thepresenceofphosphatidylglycerol(PG),andmorerecently,thesurfactant/albumin(S/A)ratio.FortheL/Sratio,iftheresultislessthan2:1,thefetallungsmaybesurfactantdeficient.ThepresenceofPGusuallyindicatesfetallungmaturity.FortheS/Aratio,theresultisgivenasmgofsurfactantpergmofprotein.AnS/Aratio<35indicatesimmaturelungs,between35-55isindeterminate,and>55indicatesmaturesurfactantproduction(correlateswithanL/Sratioof2.2orgreater).PrenatalUltrasoundThereareseveraltypesoffetalultrasound,eachwithspecificadvantagesincertainsituations.ADopplerultrasound,forexample,helpstostudythemovementofbloodthroughtheumbilicalcordbetweenthe

fetusandplacenta.Three-dimensionalultrasoundprovidesalife-likeimageofanunbornbaby.Clinicalapplications

IdentificationofpregnancyIdentificationofmultiplefetusesDeterminationoffetalage,growthandmaturityObservationofpolyhydramniosandoligohydramniosDetectionoffetalanomaliesDeterminationofplacentapreviaIdentificationofplacentalabnormalitiesLocationoftheplacentaandfetusforamniocentesisDeterminationoffetalpositionDeterminationoffetaldeath

ExaminationoffetalheartrateandrespiratoryeffortDetectionofincompletemiscarriagesandectopicpregnanciesPrenatalUltrasoundUltrasoundusesanelectronicdevicecalledatransducertosendandreceivesoundwaves.Whenthetransducerismovedovertheabdomen,theultrasonicsoundwavesthenmovethroughtheskin,muscle,bone,andfluidsatdifferentspeeds.Thesoundwavesbounceoffthefetuslikeanecho,returningtothetransducer.Thetransducerpicksupthereflectedwavesandconvertsthemintoanelectronicpicture.Acleargelisplacedbetweenthetransducerandtheskintoallowforthebestsoundconductionandsmoothmovementofthetransducer.PrenatalUltrasoundCertainfetalstructuresarecheckedduringroutineultrasonography.

Headandbrain.Thechamberswithinthebrain(ventricles),distancebetweenparietalbonesofthefetalhead(biparietaldiameter),andskinthicknessatthebackofhead(nuchalarea)areevaluatedfordefects.Heart.Thechambersandvalvesoftheheartareevaluatedanddefectsmaybeidentified.Abdomenandstomach.Thesize,location,andarrangementof

stomachanddiaphragm

arechecked.Urinarybladder.Thesizeandpresenceofthebladderisevaluated.Spine.Defectsmaybeidentifiedifpresent.Umbilicalcord.Threebloodvesselsshouldbeattachedatthefrontoftheabdomen.Kidneys.Twokidneysshouldbepresentoneithersideofthemid-spine.Otherfetalstructures.Limbsandotherpartsmayalsobescannedandevaluated./medical/charts.html#Measurement_Standards_ChartGestationalageisusuallydeterminedbythedateofthewoman'slastmenstrualperiod,andassumingovulationoccurredondayfourteenofthemenstrualcycle.SometimesawomanmaybeuncertainofthedateofherlastmenstrualperiodUltrasoundscansofferanalternativemethodofestimatinggestationalage.Themostaccuratemeasurementfordatingisthecrown-rumplengthofthefetus,whichcanbedonebetween7and13weeksofgestation.After13weeksofgestation,thefetalagemaybeestimatedusingthebiparietaldiameter(thetransversediameterofthehead),theheadcircumference,thelengthofthefemur,thecrown-heellength(headtoheel),andotherfetalparameters.[Datingismoreaccuratewhendoneearlierinthepregnancy;ifalaterscangivesadifferentestimateofgestationalage,theestimatedageisnotnormallychangedbutratheritisassumedthefetusisnotgrowingattheexpectedrateAlpha-FetalProteinaprotein

thatinhumansisencodedbytheAFPgeneTheAFPgeneislocatedontheqarmofchromosome4AFPisamajorplasmaproteinproducedbytheyolksacandtheliverduringfetaldevelopmentthatisthoughttobethefetalformofserumalbumin.Alpha-FetalProteinInpregnantwomen,fetalAFPlevelscanbemonitoredinurine.AFPisclearedstronglyfromthekidneysallowingAFPtotendtomirrorfetalserumlevels.Incontrast,maternalserumAFPlevelsaremuchlowerbutcontinuetoriseuntilaboutweek32.ThisisthoughttobebecausethemotherisnotutilizingtheAFP,andthereforeclearsitfromhersystemwithoutissue.Alpha-FetalProteinAFPinamnioticfluidhasoneortwosources.ThefetusnormallyexcretesAFPintoitsurine,henceintotheamnioticfluid.AfetuswithoneofthreebroadcategoriesofdefectsalsoreleasesAFPbyothermeans.Thesecategoriesareopenneuraltubedefect,openabdominalwalldefect,andskindiseaseorotherfailureoftheinteriororexteriorbodysurface.AbnormallyelevatedAFPinamnioticfluidcanhaveoneormoreofmanydifferentcauses:normalelevation.75%ofAFAFPtestresultsintherange2.0to4.9MoMarefalsepositives:thebabyisnormal.openneuraltubedefectopenabdominalwalldefectcongenitalnephrosisNeuraltubedefectsoneofthemostcommonbirthdefects,occurringinapproximatelyonein1,000livebirthsintheUnitedStates.ANTDisanopeninginthespinalcordorbrainthatoccursveryearlyinhumandevelopment.Inthe3rdweekofpregnancycalledgastrulation,specializedcellsonthedorsalsideofthefetusbegintofuseandformtheneuraltube.Whentheneuraltubedoesnotclosecompletely,anNTDdevelopsNeuraltubedefectsAnencephaly(withoutbrain)isaneuraltubedefectthatoccurswhentheheadendoftheneuraltubefailstoclose,usuallyduringthe23rdand26thdaysofpregnancy,resultinginanabsenceofamajorportionofthebrainandskull.Infantsbornwiththisconditionarebornwithoutthemainpartoftheforebrain-thelargestpartofthecerebrum.Infantsbornwiththisconditionareusuallyblind,deafandunconscious.Thelackofafunctioningcerebrumwillensurethattheinfantwillnevergainconsciousness.Infantsareeitherstillbornorusuallydiewithinafewhoursordaysafterbirth.Encephalocelesarecharacterizedbyprotrusionsofthebrainthroughtheskullthataresac-likeandcoveredwithmembrane.Theycanbeagroovedownthemiddleoftheupperpartoftheskull,betweentheforeheadandnose,orthebackoftheskull.Encephalocelesareoftenobviousanddiagnosedimmediately.Sometimessmallencephalocelesinthenasalandforeheadareundetected.Hydranencephalyisaconditioninwhichthecerebralhemispheresaremissingandinsteadfilledwithsacsofcerebrospinalfluid.Cordocentesis

a.

Inuterosamplingoffetalumbilicalcordbloodb.

Underultrasound,theumbilicalcordispuncturedwitha22gaugeneedleandbloodsamplesaredrawnintotuberculinsyringesc.

Samplescheckedforsickle-cell,hemophilia,fetalinfection,metabolicdisease,congenitaldefects,PO2andacid-basestatusd.

Fetalandmaternalriskis<1%MaternalEstriolSecretedinhighquantitiesbytheplacentainthelatterhalfofpregnancyNormallevelsdependonproperlyfunctioningfetalliverandadrenalglandsLevelsaredecreasedingrowthretardation,fetaldistress,andplacentalinsufficiencyMaternalbloodand/orurineiscollectedseveraltimesaweekFetaldistressisindicatedbya50-60%

dropfromprevioustestsorongoingdropInconvenient,highnumberoffalsenegativesHumanPlacentalLactogen(HPL)

Producedbytheplacenta,excretedinmaternalbloodPreparesbreastsformilkproductionLevelsincreaseuntil37weeksthenremainssameordecreasesslightlySerumlevelsareevaluatedweeklyNormalrange(term)5.4-7.0ug/mLHPL<4ug/mLafter30weeksgestationmayindicatefetalcompromiseLesspopularinrecentyears,inconvenientMRIinassessingfetalstatusUsedtoassessthestatusofsofttissuestructureandfunctionIndicatedwhenultrasoundisinsufficientUsedtodetectplacentalandfetalabnormalitiesAssessdevelopmentofthefetallungsandbrainNoriskofdamagetothefetusMeconiumStainingAssessedduringamniocentesisorthroughfluiddischargebeforedeliveryTreatwithAmnioinfusion,amethodofthinningthickmeconiumthathaspassedintotheamnioticfluidthroughpumpingofsterilefluidintotheamnioticfluid,hasnotshownabenefitintreatingMASAssessingFetalHeartRatePurposecorrelateswithfetalwell-beingThreewaystomonitorFHRi.

Dopplertransduceronmom’sabdomenii.

ECGmonitoronmom’sabdomeniii.

Smallelectrodeonfetalscalp;membranesarerupturedsothereisariskofinfectionAssessingFetalHeartRateNormalrangeis120to160bpmAnincreaseordecreaseof20to30bpmmaybeabnormalevenifinnormalrangeVariability:Fetushasaconstantlychangingheartrate(5-10bpm)Decreasedvariabilityiscausedby:a.

CNSdepressionsecondarytohypoxiab.

fetalsleepc.

immaturityd.

maternalnarcoticuseBradycardiaHeartrate<100bpmoradropof20bpmfrombaselineCausesa.

Fetalasphyxia i.

mostdangerouscause ii.

treatbygivingmomO2b.

congenitalheartdefectsc.

hypothermiaTachycardiaHeartrate>180consistentlyCausesa.

maternalfeverb.

mostcommoncausec.

infectiond.

dehydratione.

anxiety,asphyxiaf.

sympathomimeticsg.

parasympatholyticsDecelsDecelerations1.

Fetalheartrate<120bpmfor<2minutes2.

Maybethreateningorharmless,dependingonthetypeofdeceleration.3.

TypesofDecelerationsTypeIDecelerations(Early);Closelyfollowuterine contractionsinonsetandduration.Heartratedecreases to60-80bpmduringthecontraction,thenrapidlyreturns tobaselineafterthecontraction.Causedbycompression ofthefetalheadagainstthecervixduringthecontraction (vagalresponse).Benign,itdoesn’tindicatehypoxiaDecelsTypeIIDecelerations(Late)Occur10-30afterstartofcontractionwithaslowreturntobaselineEvenasmalldecreaseof10-20bpmindicatesaproblem.SecondarytouteroplacentalinsufficiencyCausedbycompressionofthevesselsoftheuterusandplacentaduringthecontractionLeadstodecreasedtransferofO2tothefetusandfetalasphyxiaDecelsTypeIIIDecelerations(Variable)DecelerationsindependentofcontractionsRandominonset,durationandseverityCausedbycompressionoftheumbilicalcordUmbilicalcordwrappedaroundthefetusesneckorcompressedbetweenthepelvisandbodypartDangerdependsonfrequencyandseverityTurnmomsidetosideorplaceinkneestochestpositiontoalleviatecordcompressionScalppHPurposeUsedinconjunctionwithfetalheartmonitoringAssessesfetalasphyxiaIndicationsAbsenceofbaselinevariabilityLatedecelerationswithdecreasingvariabilityAbnormalFHMtracingsProcedureMotherplacedinlithotomypositionFetalheadvisualizedthroughthecervixScalpincisionmadeBloodcollectedinheparinizedcapillarytubelithotomyposition

ScalppHPoorgasexchangeleadstoincreasedPaCO2andlacticacidosis(mixedacidosis)InterpretationofFetalScalppHpHInterpretation7.25Normal7.20-7.24Slightasphyxia<7.20SevereFetalPositionBreechTocolysis

medicationsusedtosuppressprematurelaborTheyaregivenwhendeliverywouldresultinprematurebirthThetherapyalsobuystimefortheadministrationofbetamethasone,aglucocorticoiddrugwhichgreatlyacceleratesfetallungmaturity,buttakesonetotwodaystowork.Thesuppressionofcontractionsisoftenonlypartialandtocolyticscanonlybereliedontodelaybirthforseveraldays.Dependingonthetocolyticusedthemotherorfetusmayrequiremonitoring,asforinstancebloodpressuremonitoringwhennifedipineisusedasitreducesbloodpressure.Inanycasetheriskofpretermlaboralonejustifieshospitalization.CordGasUmbilicalcordbloodgassamplesareanalyzedforpH,PCO2andPO2.Bicarbonate,baseexcessandoxygensaturationareallcalculatedfromthemeasuredparameters.Oxygensaturationiscalculatedasthoughthehemoglobinwereallhemoglobinratherthanfetalhemoglobin;consequently,thecalculatedoxygensaturationinumbilicalcordbloodsignificantlyunderestimatesthetruevalue.Thebicarbonateandthebaseexcessaregenerallyapproximatelythesameinumbilicalvenousandarterialblood,butifoneisworse(agreatermetabolicacidosis),itisthearterialblood.CordGasValuesVenouspH7.35(+/-)0.05PCO238(+/-)5.6PO229(+/-)5.9BE-4(+/-)2HCO320(+/-)2.1ArterialpH7.28(+/-)0.05PCO249(+/-)8.4PO218(+/-)6.2BE-4(+/-)2HCO322(+/-)2.5NotethatthebicarbonatevalueismisleadinglyelevatedwheneverthePCO2isexceptionallyhigh,becausethePCO2isinequilibriumwithbicarbonate.Assoonasthebabyiswellventilated,thebicarbonatewill"disappear,"howeverthebaseexcesswillnotchangeuntilthetruemetabolicacidosisimproves.InfantAssessmentDubowitz/BallardScore

/ballard.htmlNewBallardScore

MaturationalAssessmentofGestationalAge

TheNewBallardScoreisasetofproceduresdevelopedbyDr.JeanneLBallard,MDtodetermineGestationalAgethroughneuromuscularandphysicalassessmentofanewborninfant./Pages/videos.aspxPerformingtheAssessmentofNeuromuscularMaturityPostureTotalbodymuscletoneisreflectedintheinfant'spreferredpostureatrestandresistancetostretchofindividualmusclegroups.Asmaturationprogresses,thefetusgraduallyassumesincreasingpassiveflexortonethatproceedsinacentripetaldirection,withlowerextremitiesslightlyaheadofupperextremities.Forexample,veryearlyingestationonlytheanklesareflexed.Kneeswillflexaswristsjustbegintoflex.Hipflexion,thenabductionarejustaheadofelbow,thenshouldergirdleflexion.Thepreterminfantprimarilyexhibitsunopposedpassiveextensortone,whiletheinfantapproachingtermshowsprogressivelylessopposedpassiveflexortone.AnkleflexionPostureToelicitthepostureitem,theinfantisplacedsupineandtheexaminerwaitsuntiltheinfantsettlesintoarelaxedorpreferredposture.Iftheinfantisfoundsupine,gentlemanipulation(flexifextended;extendifflexed)oftheextremitieswillallowtheinfanttoseekthebaselinepositionofcomfort.Hipflexionwithoutabductionresultsinthefrog-legpositionasdepictedinposturesquare#3.Hipadductionaccompanyingflexionisdepictedbytheacuteangleatthehipsinposturesquare#4.Thefigurethatmostcloselydepictstheinfant'spreferredpostureisselected.SquareWindow

Wristflexibilityand/orresistancetoextensorstretchingareresponsiblefortheresultingangleofflexionatthewrist.Theexaminerstraightenstheinfant'sfingersandappliesgentlepressureonthedorsumofthehand,closetothefingers.Fromextremelypre-termtopost-term,theresultinganglebetweenthepalmoftheinfant'shandandforearmisestimatedat;>90°,90°,60°,45°,30°,and0°.Theappropriatesquareonthescoresheetisselected.ArmRecoilThismaneuverfocusesonpassiveflexortoneofthebicepsmusclebymeasuringtheangleofrecoilfollowingverybriefextensionoftheupperextremity.Withtheinfantlyingsupine,theexaminerplacesonehandbeneaththeinfant'selbowforsupport.Takingtheinfant'shand,theexaminerbrieflysetstheelbowinflexion,thenmomentarilyextendsthearmbeforereleasingthehand.Theangleofrecoiltowhichtheforearmspringsbackintoflexionisnoted,andtheappropriatesquareisselectedonthescoresheet.Theextremelypre-terminfantwillnotexhibitanyarmrecoil.Square#4isselectedonlyifthereiscontactbetweentheinfant'sfistandface.Thisisseenintermandpostterminfants.PoplitealAngle

Thismaneuverassessesmaturationofpassiveflexortoneaboutthekneejointbytestingforresistancetoextensionofthelowerextremity.Withtheinfantlyingsupine,andwithdiaperre-moved,thethighisplacedgentlyontheinfant'sabdomenwiththekneefullyflexed.Aftertheinfanthasrelaxedintothisposition,theexaminergentlygraspsthefootatthesideswithonehandwhilesupportingthesideofthethighwiththeother.Careistakennottoexertpressureonthehamstrings,asthismayinterferewiththeirfunction.Thelegisextendeduntiladefiniteresistancetoextensionisappreciated.Insomeinfants,hamstringcontractionmaybevisualizedduringthismaneuver.Atthispointtheangleformedatthekneebytheupperandlowerlegismeasured.ScarfSignThismaneuverteststhepassivetoneoftheflexorsabouttheshouldergirdle.Withtheinfantlyingsupine,theexamineradjuststheinfant'sheadtothemidlineandsupportstheinfant'shandacrosstheupperchestwithonehand.thethumboftheexaminer'sotherhandisplacedontheinfant'selbow.Theexaminernudgestheelbowacrossthechest,fellingforpassiveflexionorresistancetoextensionofposteriorshouldergirdleflexormuscles.Thepointonthechesttowhichtheelbowmoveseasilypriortosignificantresistanceisnoted.Landmarksnotedinorderofincreasingmaturityare:fullscarfattheleveloftheneck(-1);contralateralaxillaryline(0);contralateralnippleline(1);xyphoidprocess(2);ipsilateralnippleline(3);andipsilateralaxillaryline(4).HeeltoEarThismaneuvermeasurespassiveflexortoneaboutthepelvicgirdlebytestingforpassiveflexionorresistancetoextensionofposteriorhipflexormuscles.Theinfantisplacedsupineandtheflexedlowerextremityisbroughttorestonthemattressalongsidetheinfant'strunk.Theexaminersupportstheinfant'sthighlaterallyalongsidethebodywiththepalmofonehand.Theotherhandisusedtograsptheinfant'sfootatthesidesandtopullittowardtheipsilateralear.Theexaminerfellsforresistancetoextensionoftheposteriorpelvicgirdleflexorsandnotesthelocationoftheheelwheresignificantresistanceisappreciated.Landmarksnotedinorderofincreasingmaturityincluderesistancefeltwhentheheelisatornearthe:ear(-1);nose(0);chinlevel(1);nippleline(2);umbilicalarea(3);andfemoralcrease(4).PhysicalMaturity-SkinMaturationoffetalskininvolvesthedevelopmentofitsintrinsicstructuresconcurrentwiththegraduallossofitsprotectivecoating,thevernixcaseosa.Hence,itthickens,driesandbecomeswrinkledand/orpeels,andmaydeveloparashasfetalmaturationprogresses.Thesephenomenamayoccuratvaryingpacesinindividualfetusesdependinginpartuponthematernalconditionandtheintrauterineenvironment.PhysicalMaturity-SkinBeforethedevelopmentoftheepidermiswithitsstratumcorneum,theskinistransparentandadheressomewhattotheexaminer'sfinger.Lateritsmoothes,thickensandproducesalubricant,thevernix,thatdissipatestowardtheendofgestation.Attermandpost-term,thefetusmayexpelmeconiumintotheamnioticfluid.Thismayaddanacceleratingeffecttothedryingprocess,causingpeeling,cracking,dehydration,andimpartingaparchment,thenleathery,appearancetotheskin.Forscoringpurposes,thesquarewhichdescribestheinfant'sskinthemostcloselyshouldbese