PlacentaPlacenta DiseasesPlacenta PreviaPlacenta AccretaPregnancyPlacenta, RetainedTrophoblastsChorionic VilliDelayed DiagnosisPrenatal DiagnosisMaternal-Fetal ExchangeEarly DiagnosisPregnancy ProteinsPlacentationSensitivity and SpecificityDiagnosisFetusGestational AgePre-EclampsiaRetrospective StudiesPregnancy Trimester, ThirdExtraembryonic MembranesChorionPregnancy Trimester, FirstInfant, NewbornDiagnostic ErrorsPregnancy, AnimalPlacental LactogenChoriocarcinomaDeciduaPlacental CirculationFetal Growth RetardationImmunohistochemistryBiopsyTime FactorsTomography, X-Ray ComputedUterusUltrasonography, PrenatalPredictive Value of TestsPolymerase Chain ReactionFetal DiseasesNursing DiagnosisDiagnosis, Computer-AssistedReproducibility of ResultsPregnancy Trimester, SecondAmniotic FluidAbortion, VeterinaryFetal DevelopmentRisk FactorsCesarean SectionPreimplantation DiagnosisProspective StudiesPrognosisPregnancy ComplicationsMagnetic Resonance ImagingMolecular Sequence DataPlacental HormonesTreatment OutcomeHydatidiform MoleFollow-Up StudiesFetal DeathAmnionPregnancy Complications, ParasiticBase SequenceLabor, ObstetricUmbilical CordCase-Control StudiesPregnancy Complications, InfectiousCohort StudiesFatal OutcomeBiological MarkersBiopsy, NeedleGenomic ImprintingIncidenceChorioamnionitisPregnancy OutcomeYolk SacEnzyme-Linked Immunosorbent AssayFetal BloodAborted FetusUltrasonographyPlacental ExtractsReverse Transcriptase Polymerase Chain ReactionAge FactorsUterine NeoplasmsPrevalenceAllantoisAmino Acid SequenceUterine HemorrhageTissue DistributionGene ExpressionROC CurveAcute DiseaseSyndromeFalse Positive ReactionsClinical Laboratory TechniquesPostpartum HemorrhageSeverity of Illness IndexPregnancy TrimestersUnited States