妇产科学教学课件：12 Fetal distress

FetaldistressFetaldistressisdefinedasdepletionofoxygenandaccumulationofcarbondioxide,leadingtoastateof

“hypoxiaandacidosis”

duringintra-uterinelife.Acutefetaldistress:deliveryperiodChronicfetaldistress:latepregnancy,acutedistressinlabor.Incidencerate:2.7%～38.5%DefinitionImportanceTheLeadingcauseofperinataldeathThemajorcauseofretardedchildHypoxia(pre-labor,inlabor,afterbirth):90%Severeasphyxia:4.1%mentalretardationMaternalfactorsMicrovascularischemia:PIH,GDM,prolongedpregnancyLowoxygencarriedbyRBC:cardiacinsufficiency,severeanemiaAcutebleedingandshock:placentaprevia,placentalabruptionMisuseofanestheticobstructedofUtero-placentalbloodflow:discordantcontraction(misuseofpitocin)EtiologyPlacental、umbilicalandfetalfactorsObstructedofumbilicalbloodflow:prolapseofcord,circularofcordDysfunctionofplacentaFetalfactors:malformation,hemolyticanemia(ABO)IntrauterineinfectionEtiologyHypoxia、accumulationofcarbondioxide￬RespiratoryAcidosis→Metabolicacidosis(irreversibledamage)￬FHR￪(sympatheticN￪,CO2)→

FHR￬（vagusN￪,hypoxia）

￬Intestinalperistalsis（肠蠕动）￪￬Relaxationoftheanalsphincter（肛门括约肌）￬Meconium(胎粪)aspiration￬FetalorneonatalpneumoniaPathogenesisAcutefetaldistressChronicFetaldistressPathogenesis

FGR(Fetalgrowthretardation)ClinicalmanifestationAcutefetaldistress(1)FHR(baselineandvariability)FHR>160beats/min(tachycardia)<110beats/min(bradycardia)FHRmonitoring:(ED):fetalheadtobecrushedinlabor(reversible)(LD):RepeatedlatedecelerationPlacentadysfunction(VD):VariabledecelerationUmbilicalfactors

FetalheartratebaselineandvariabilityAdverseoutcomeFHR<100bpmVariability<5bpmRepeatedLDorVD.Earlydeceleration，EDLatedeceleration，LDVariabledeceleration，VDClinicalmanifestationAcutefetaldistress(2)MeconiumstainingoftheamnioticfluidgradeI、II、III(3)Fetalmovement

Frequently→decreaseandweaken(4)AcidosisFBS(fetalbloodsample)

pH<7.20pO2<10mmHg(15~30mmHg)

pCO2>60mmHg(35~55mmHg)

ClinicalmanifestationChronicfetaldistress(1)Placentalfunction(24hE3<10mgorE/C<10)

(2)FHR:LD(3)BPS:≤4(4)Fetalmovement:decreaseorweaken(5)umbilicalarterybloodflow:S/D>2ManagementGeneraltreatment:Lieontheleftside,oxygenuptakeEtiologicaltreatment:RemovetheinducedfactorspromptlyCorrecttheacidosis:5%NaHCO3250MLManagementTerminatethepregnancyFHR>160or<110bpm,meconiumstaining(II~III)MeconiumstaininggradeIII,amnioticfluidvolume<2cmFHR<100bpmcontinuallyRepeatedLDandsevereVDBaselinevariabilitydisappearwithL