Fetal HeartHeart Rate, FetalHeartFetal MonitoringCardiotocographyHeart RatePregnancyUltrasonography, PrenatalHeart Defects, CongenitalEchocardiography, Four-DimensionalGestational AgeFetal DiseasesFetal MovementFetal HypoxiaFetal DistressFetusUmbilical ArteriesAnimals, NewbornHeart FailurePostnatal CareHeart BlockCanrenoic AcidPregnancy Trimester, SecondEchocardiography, Three-DimensionalHeart DiseasesMagnetocardiographyPregnancy Trimester, ThirdUltrasonography, DopplerHeart TransplantationMyocardiumLabor, ObstetricHeart ValvesPregnancy Trimester, FirstFetal DevelopmentInfant, NewbornCardiac VolumeMaternal-Fetal ExchangePrenatal DiagnosisPregnancy OutcomeBradycardiaEchocardiographySheepFetal Growth RetardationAbortion, ThreatenedMyocytes, CardiacApgar ScoreBlood Flow VelocityHeart AtriaProspective StudiesGene Expression Regulation, DevelopmentalEchocardiography, Doppler, ColorPregnancy ComplicationsRats, Sprague-DawleyPerinatologyMyocardial ContractionHemodynamicsEmbryonic and Fetal DevelopmentTime FactorsCrown-Rump LengthElectronics, MedicalHeart SeptumPregnancy, High-RiskAnalgesia, ObstetricalPlacental CirculationAgingCardiomegalyRNA, MessengerAnesthesia, ObstetricalCesarean SectionHeart AuscultationTocolytic AgentsUmbilical CordDown SyndromeSheep, DomesticSensitivity and SpecificityHeart Arrest, InducedHeart Function TestsUltrasonography, Doppler, ColorSufentanilFetal DeathOrgan SizeReproducibility of ResultsFeasibility StudiesReference ValuesHeart VentriclesRisk FactorsUltrasonographyTachycardiaDelivery, ObstetricMyocardial IschemiaImmunohistochemistryRats, WistarPrenatal Exposure Delayed EffectsPregnancy in DiabeticsAnesthesia, EpiduralObstetricsMeconiumMice, Inbred C57BLObstetric Labor ComplicationsEchocardiography, Doppler