Ultrasonography, Doppler, ColorUltrasonography, DopplerBlood Flow VelocityEchocardiographyUltrasonography, PrenatalOphthalmic ArteryEchocardiography, Doppler, ColorColorDoppler EffectUltrasonography, Doppler, PulsedSensitivity and SpecificityPregnancyEchocardiography, TransesophagealProspective StudiesEchocardiography, Three-DimensionalEchocardiography, DopplerEchocardiography, Doppler, PulsedRegional Blood FlowUltrasonography, Doppler, TranscranialUterusGestational AgeUltrasonographyPredictive Value of TestsEchocardiography, StressPulsatile FlowColor PerceptionUltrasonicsUmbilical ArteriesMitral ValveObserver VariationReproducibility of ResultsFetal HeartVentricular Function, LeftContrast MediaLaser-Doppler FlowmetryUltrasonography, InterventionalVentricular Dysfunction, LeftDiastoleDobutamineFetal DiseasesStroke VolumeHemodynamicsPlacental CirculationHeart VentriclesCardiac CatheterizationSystoleImaging, Three-DimensionalPregnancy Trimester, SecondVascular ResistanceColor VisionHeart Defects, CongenitalFeasibility StudiesCoronary CirculationEchocardiography, Four-DimensionalAdnexa UteriMitral Valve InsufficiencyArteriesColor Perception TestsEchoencephalographyMicrobubblesAdnexal DiseasesImage EnhancementHigh-Intensity Focused Ultrasound AblationHeart Septal Defects, AtrialAngiographyBlood PressureTricuspid Valve InsufficiencyCerebrovascular CirculationHeart DiseasesUltrasonic TherapyHeart Valve DiseasesAortic ValveUltrasonography, Doppler, DuplexHeart Rate, FetalTime FactorsMiddle Cerebral ArteryHeart AtriaMyocardial ContractionImage Interpretation, Computer-AssistedPortal VeinFollow-Up StudiesFetal Growth RetardationCardiac OutputOrbitSulfur HexafluorideColor Vision DefectsRetrospective StudiesRetinal ArteryArteriovenous MalformationsRheologyPulmonary ArteryHair ColorElectrocardiographyInfant, NewbornTreatment OutcomeHeart Valve ProsthesisPregnancy Trimester, ThirdReference ValuesPlacenta, RetainedTransducers