Fetal HeartHeart Rate, FetalPregnancyHeartFetal MonitoringPregnancy OutcomePregnancy ComplicationsCardiotocographyUltrasonography, PrenatalPregnancy, AnimalHeart RateGestational AgePregnancy Trimester, FirstPregnancy Trimester, ThirdHeart Defects, CongenitalPregnancy Trimester, SecondEchocardiography, Four-DimensionalPregnancy, EctopicFetal DiseasesFetal MovementFetal DistressFetal HypoxiaFetusUmbilical ArteriesPregnancy RatePregnancy in DiabeticsPregnancy, MultiplePregnancy Complications, CardiovascularPregnancy TrimestersPregnancy TestsPregnancy, High-RiskHeart FailureLabor, ObstetricPregnancy, TubalInfant, NewbornAbortion, SpontaneousHeart BlockPregnancy Complications, NeoplasticMaternal-Fetal ExchangeCanrenoic AcidPregnancy in AdolescenceUltrasonography, DopplerHeart DiseasesFetal DevelopmentPregnancy Complications, InfectiousEchocardiography, Three-DimensionalMagnetocardiographyPrenatal DiagnosisFetal DeathFetal Growth RetardationHeart TransplantationPlacentaHeart ValvesPregnancy ProteinsAbortion, ThreatenedPregnancy, UnplannedMyocardiumPre-EclampsiaProspective StudiesPregnancy, UnwantedCesarean SectionCardiac VolumeUterusSheepPregnancy Complications, HematologicPrenatal CareBradycardiaApgar ScorePlacental CirculationEmbryo TransferEchocardiographyCrown-Rump LengthPregnancy, ProlongedMaternal AgePregnancy, TwinFertilization in VitroBlood Flow VelocityDelivery, ObstetricRisk FactorsTime FactorsAbortion, InducedPregnancy, AbdominalHeart AtriaPregnancy Complications, ParasiticPerinatologyEchocardiography, Doppler, ColorMyocytes, CardiacPregnancy MaintenanceEmbryonic and Fetal DevelopmentDown SyndromeEmbryo ImplantationAmniotic FluidHemodynamicsRetrospective StudiesAnesthesia, ObstetricalMyocardial ContractionObstetric Labor ComplicationsUltrasonography, Doppler, ColorSensitivity and SpecificityUmbilical Cord