Vena Cava, InferiorVena Cava, SuperiorVena Cava FiltersDuctus ArteriosusAzygos VeinDuctus Arteriosus, PatentSuperior Vena Cava SyndromeFetal HeartVenae CavaeUltrasonography, PrenatalUltrasonography, Doppler, PulsedRenal VeinsHepatic VeinsUmbilical VeinsPhlebographyBlood Flow VelocityBudd-Chiari SyndromeVascular NeoplasmsVenous ThrombosisUltrasonography, DopplerIliac VeinVeinsPulmonary EmbolismGestational AgePulsatile FlowPregnancyFetal Growth RetardationVascular MalformationsPortal SystemFetusHeart Defects, CongenitalPortal VeinPregnancy Trimester, FirstUmbilical ArteriesNuchal Translucency MeasurementFetal DiseasesLeiomyosarcomaDevice RemovalTomography, X-Ray ComputedFemoral VeinHeart AtriaPlacental CirculationFetal MonitoringLiver CirculationUltrasonography, Doppler, ColorHeart Rate, FetalHeart Septal Defects, AtrialHeterotaxy SyndromePlacental InsufficiencyFetofetal TransfusionConstriction, PathologicHydrops FetalisScimitar SyndromeNasal BoneTricuspid Valve InsufficiencyRegional Blood FlowTreatment OutcomeCrown-Rump LengthCardiotocographyInfant, NewbornPregnancy OutcomeSitus InversusPulmonary VeinsInferior ColliculiPregnancy Trimester, SecondRetroperitoneal NeoplasmsAtrial FlutterVenous PressureRetrospective StudiesEchocardiography, DopplerAnastomosis, SurgicalHeart NeoplasmsLeiomyomatosisHeart Bypass, RightHemodynamicsThrombosisChromosome DisordersNeckConstrictionPulmonary ArteryNuchal CordProspective StudiesThrombectomyForeign-Body MigrationPregnancy Trimester, ThirdLabor Stage, FirstCatheterization, Central VenousProsthesis ImplantationVascular DiseasesVascular Surgical ProceduresDogsEchocardiographyAnticoagulantsReplantationArteriovenous FistulaBlood Vessel Prosthesis ImplantationVascular GraftingLiverTrisomyBrachiocephalic Veins