FetusFetal BloodGestational AgePregnancyCordocentesisMaternal-Fetal ExchangeRNA, MessengerFetal Tissue TransplantationPlacentaComplicityAborted FetusFetal DiseasesBlood Transfusion, IntrauterineAmniotic FluidFetomaternal TransfusionDirected Tissue DonationHydrops FetalisRh IsoimmunizationErythroblastosis, FetalPrenatal DiagnosisPregnancy, AnimalLifeFetoscopyHeart Rate, FetalPersonhoodSheepAbortion, VeterinaryBeginning of Human LifeFetal WeightFetal HypoxiaFetal DeathFetal Growth RetardationUmbilical ArteriesBlood Specimen CollectionUmbilical CordPregnancy Trimester, SecondFetal ResearchEmbryonic and Fetal DevelopmentPlacental CirculationChorionic VilliFetal DevelopmentPregnancy Trimester, ThirdCardiotocographyUltrasonography, PrenatalCivil RightsUterusPregnancy Trimester, FirstFetal Stem CellsVitamin K Deficiency BleedingPregnant WomenBlood Gas AnalysisTrophoblastsAbortion, InducedInfant, NewbornLabor, ObstetricLiverBrain Tissue TransplantationTherapeutic Human ExperimentationFetal HemoglobinExtraembryonic MembranesHemoglobinopathiesNontherapeutic Human ExperimentationErythema InfectiosumFetal ResorptionUltrasonography, DopplerFetal HeartTissue DistributionSocial Control, FormalAmniocentesisAcidosisAnesthesia, ObstetricalFetofetal TransfusionAbortion, LegalUmbilical VeinsEthics, MedicalErythrocyte CountBlood Flow VelocityPlacenta DiseasesMoral ObligationsErythroblastsAdvisory CommitteesYolk SacPulsatile FlowThymus GlandHematocritOxygenFederal Government