自然生产.ppt

自然生產,楊明智,FactorsrelatedtoBirth,PassageBirthcanalPassengerFetusPowerForceofuterinecontraction,PelvicAnatomy,4bonessacrum,coccyx,twoinnominatebonesThetruepelvisisboundedabovebythepromontoryandalaeofthesacrum,thelineaterminalis,andtheuppermarginsofthepubicbones,andthelowerbythepelvicoutlet.Anobliquelytruncated,bentcylinderwithanteriorwallheight5cm,andtheposteriorwall,10cm.ConvergedsidewallsDistancebetweenischialspinestheshortestdiameterofthepelviccavity,PelvicJoints,Symphysispubisconsistsoffibrocartilage,thesuperiorandinferior(arcuateligament)pubicligaments.Sacroiliacjointsbetweenthesacrumandtheiliacportionoftheinnominatebones.Relaxationofthepelvicjointsresultsfromhormonalchange,commencedinearlyhalfofpregnancy,andincreasedduringthelast3m,regressedafterparturition.Sacroiliacjointmobilitycausedbyupwardglidingmovementsofthejoint,greatestindorsallithotomyposition,andmaythediameteroftheoutletby1.5to2cm.(Shoulderdystocia),PlanesandDiametersofthePelvis,TheplaneofthepelvicinletthesuperiorstraitTheplaneofthepelvicoutlettheinferiorstraitTheplaneofthemidpelvistheleastpelvicdimensionsTheplaneofgreatestpelvicdimensionofnoobstetricalsignificance,PelvicInlet,4typesinshapegynecoid(50%),anthropoid,android,platypelloid.Mostareintermediatetype.4diametersanteroposterior,transverse,and2obliquesObstetricalconjugatetheshortestdistancebetweenpromontoryandsymphysispubis.Estimatedbysubstracing1.5to2cmfromthediagonalconjugate.TrueconjugatetheA-Pdiameterofthepelvicinlet,Midpelvis,Planeoftheleastpelvicdimensions,attheleveloftheischialspines.Theinterspinousdiameter,10cmorso,isthesmallestdiameterofthepelvis.Theanteroposteriordiameter,11.5cm.Theposteriorsagittaldiameterisaround4.5cm.,PelvicOutlet,Consistsoftwotriangleswithacommonbase,alinedrawnbetweenthetwoischialtuberosities.Theapexoftheposteriortriangleisthetipofthesacrum,thelateralboundariesarethesacrosciaticligamentsandtheischialtuberosities.Theanteriortriangletheareaunderthepubicarch.3diametersA-P,trans.,posteriorsagittal,PelvicShapes,Caldwell-MoloyclassificationAnteriorsegmentTransversediameterPosteriorsegment1.Gynecoidpelvissuitedfordeliveryofmostfetuses,50%2.Androidpelvispoorprognosisforvaginaldelivery3.AnthropoidpelvisAPdiametertrans.diameter,1/34.PlatypelloidpelvisshortAPdiameterandwidetransversediameter,3%,Pelvimetry,X-rayComputedtomographyUltrasoundMagneticresonance,Passenger-Fetus,Fetalattitude-Posture,habitusLieofthefetus-TherelationofthelongaxisofthefetustothatofthemotherPresentation-Theportionthefetuscanbefeltthroughthecervixonvaginalexamination.Position-Therelationofanarbitrarilychosenportionofthepresentingpartofthefetustotherightorleftsideofthematernalbirthcanal.Formoreaccurately-Anterior,transverse,posterior,ReasonsforthePredominanceofCephalicPresentation,PiriformshapeduterusThebreechanditsflexedextremitiesisbulkierthanthecephalicpoleandmoremovable.Morecrowdedamnioticcavityafter32ndweekofgestation,DiagnosisofFetalPresentationandPosition,AbdominalpalpationLeopoldmaneuversVaginalexaminationafterthecommencementoflaborAuscultationImagingstudiesultrasonography,plainKUB,CTscan,magneticresonanceimaging,NORMALDELIVERY,PHYSIOLOGYOFPARTURITION,StructureofUterus,Corpus:*Myometrium-Smoothmusclecells,matrix.*Endometrium(Decidua)*SerosaCervix:*Endocervicalepitheliallayer*Fibromuscularlayer*Squamousepitheliallayer*Collagenandextracellularmatrix,Decidua,DerivedfromendometriumIncreased&enlargedstromalcells,glands,andbloodvessels.Deciduabasilis-Spiralarteries,venouslakeDeciduacapsularisDeciduavera(parietalis)Function-Establishmentofpregnancy-Immunologicbarrier-Secreteprolactin,relaxin,PG,receptorsforhormones,CervixofUterus(1),RetainedtheproductofconceptionMuscularfibers-ComefromthecorpusCollagenfibers-IncreaseduterinetensionGlycosaminoglycans-FirmconsistencyCervicalripening-Takingplaceduringthelastweeksofgestation-Glycosaminoglycans,dermatansulfateandchondroitinarereplacedbyhyaluronicacid-softconsistencyanddistensible,CervixofUterus(2),Cervicalripening(cont)-Promotedbyrelaxin(?)andestrogen-Inhibitedbyprogesterone-Acceleratedby1.Metreurynter(balloontraction)2.Laminariarod3.Polyvinylalcoholsponge+MgSO4(?)4.Dehydroepiandrosterone(DHEA)(JPN)5.ProstaglandinE2localapplication6.Relaxin(Porcinerelaxin)(?),GapJunctions,Cell-to-cellcontactPoresbetweenthecytoplasmsofthetwocellPermittingrapidtransmissionofelectricalimpulsesandchemicalsignalsfromonecelltothenext.AbsentthroughoutpregnancyuntiltermorpretermlaborProgesterone,NSAIDpreventsformationEstrogen,PGE2,thromboxanesstimulategapjunctionformation,Excitation-Contraction,IntracellularfreeCaionislow.TheleveloffreeCaioncanberaisedby*Concentrationgradientinflux*Voltage-dependentCaionchannels*Receptor-operatedCaionchannels*Releasedfromintracellularstores,PhysiologyofLabor,NeuralMechanism-NoinfluenceonmyometrialfunctionduringparturitionHormonalfactors-Nodirecteffectoncontractilitybutexertaregulatoryinfluence-bywayofsynthesisofproteins,receptors,phospholipids,andprostaglandinprecursors,RelaxingHormones,Catecholamines-Actonalpha-andbeta-receptors.Estrogens(?)stimulatealpha-receptorformation.Progesteroneenhancesbeta-receptorsdominanceEpinephrine-Endogenousbeta-agonistBeta-blocker-Uterinecontractility,RelaxingHormones(2),Relaxin-Producedbycorpusluteuminpregnancyandisfoundindeciduaandplacenta.Itsimportanceinhumanparturitionisnotclearyet.,OxytocicHormones,ProstaglandinEAlpha-adrenergicneurotransmittersProstaglandinFThromboxaneA,OxytocinAngiotensinIIVasopressinBradykinin,Oxytocin,GreatpotencyforuterinecontractionOxytocinasePulsatilesecretorypatternActiononuterinemyometriumStimulatePLC(phospholipaseC)-hydrolysisofphosphatidylinostitolindecidua-mobilefreearachidonicacid-prostaglandinsynthesis*IncreaseintracellularCaionconc.,OxytocinReceptors,Presentinbothmyometriumandendometrium.Estrogenanduterinedistension-increaseoxytocinreceptorsProgesteroneinhibitstheformationofreceptors(inanimal).Thereceptorincreasedthroughoutpregnancy*Atterm-80to100foldhigher*Highestinearlylabor*Inpretermlabor-2to3timeshigher,Prostaglandins,PGE2,PGF2,PGI2,thromboxanePGE2is10timesaspotentasPGF2.PGF2isthemainprostaglandinreleasedduringlabor.Actiononmyometrium-*IncreaseintracellularfreeCaion-Openingcalciumchannel-ReleaseCafromintracellularvesiclesReceptors-Significantlowerduringpregnancy.PGE2hashigheraffinity.,PGandHumanParturition,PGincreasesstrikinglyduringlaborinamnioticfluid,maternalblood,urineandinintrauterinetissues.PG(E2,F2)evokemyometrialcontractionatanystageofpregnancy.Administrationroutes-Oral,intraamnioticinstillation,IV,orvaginalsuppository.InhibitionofPGsynthesis-Prolongationofpregnancyorstoplabor,NORMALDELIVERY,NORMALLABOR,Lightening,Occursafewweeksbeforetheonsetoflabor-Reducedfundosymphysisdistance(FSD)ChangeinabdominalshapeFetalheaddescentConsequenceofthedevelopmentofawell-formedloweruterinesegmentAmnioticfluidvolumereduced.,SingsofLabor,PassageofthemucusplugBloodyshowIntermittentlowbackpainIntermittentlowabdominalpainRuptureofthemembranes,TrueLabor,FalselaborDefinitionoflaborUterinecontractionsthatbringaboutdemonstrableeffacementanddilatationofthecervix.DublinPainfuluterinecontractionsaccompaniedbyanyoneofthefollowing:1.Rupturedmembranes,2.Bloodyshow,3.Completecervicaleffacement.InUS-Intactmembraneswithcervicaldilatationof3to4cmorgreater-onsetoflaborcommenceswiththetimeofadmission.,Falselaborvs.Truelabor,CausesofLaborPain,HypoxiaofthecontractedmyometriumCompressionofnervegangliaintheCxandtheloweruterusbytheinterlockingmusclebundlesStretchingoftheCxduringdilatationStretchingoftheoverlyingperitoneum,CharacteristicsofLabor,InvoluntaryPacemaker-Agroupofhighlyexcitablemyometrialcellsneartheuterotubaljunction-propagatebygapjunctionsFergusonreflex-MechanicalstretchingthecervixenhancingtheuterineactivityDiminishingintervalsDuration-30to90sec/contractionPressure-20to60mmHg,ave.40mmHg.,DifferentiationofUterineActivity,Uppersegment-Activesegment,contracts,retractsandexpelsthefetus.Myometrialfibersbecomeshorterandthicker.Lowersegment-Passivesegment,relaxed,dilatedandgreatlyexpanded,thinned-outforthepas