Pulsatile FlowBlood Flow VelocityModels, CardiovascularRegional Blood FlowUltrasonography, Doppler, ColorUltrasonography, Doppler, PulsedReplica TechniquesRheologyUltrasonography, DopplerUmbilical ArteriesPlacental CirculationUltrasonography, PrenatalStress, MechanicalHemorheologyUterine ArteryArteriesModels, AnatomicFetal Growth RetardationMiddle Cerebral ArteryHeart-Assist DevicesShear StrengthBlood PressureHemodynamicsPulmonary CirculationUterusPericytesPregnancyEquipment DesignFlow CytometryVascular ResistanceGestational AgeVeinsUltrasonography, Doppler, TranscranialPhantoms, ImagingOphthalmic ArteryEchocardiography, Doppler, ColorPressureCerebrovascular CirculationCarotid ArteriesCoronary CirculationFetal HeartReproducibility of ResultsBlood Vessel ProsthesisBlood VesselsPre-EclampsiaPlacental InsufficiencyFemoral ArteryAortaPregnancy Trimester, FirstHeart Valve ProsthesisEndothelium, VascularPregnancy Trimester, SecondPerfusionIntracranial AneurysmTime FactorsMaterials TestingHeart Rate, FetalBlood CirculationLaser-Doppler FlowmetryFetusBiomechanical PhenomenaDogsCerebral ArteriesSwineComputer SimulationBiliopancreatic DiversionProsthesis DesignProspective StudiesNitric Oxide Synthase Type IIIPregnancy Trimester, ThirdReference ValuesCoronary VesselsPulseLuteinizing HormoneGene FlowFetal DiseasesEchoencephalographyCattleModels, BiologicalPregnancy OutcomePeriodicityActivity CyclesPregnancy, High-RiskVascular StiffnessRenal ArteryPregnancy-Associated Plasma Protein-ACells, CulturedSensitivity and SpecificityUltrasonography, Doppler, DuplexPulse Wave AnalysisMesenteric Artery, SuperiorUltrasonography