Embryo TransferPregnancySingle Embryo TransferFertilization in VitroPregnancy RatePregnancy OutcomeEmbryo ImplantationPregnancy, MultipleEmbryo, MammalianCryopreservationSperm Injections, IntracytoplasmicPregnancy ComplicationsPregnancy, AnimalBlastocystPregnancy, EctopicLive BirthInfertility, FemaleInfertilityEmbryo, NonmammalianOvulation InductionAbortion, SpontaneousTwinsCleavage Stage, OvumOocyte DonationChick EmbryoZygote Intrafallopian TransferReproductive Techniques, AssistedReproductive TechniquesPregnancy, TubalPregnancy TestsEmbryonic and Fetal DevelopmentEmbryonic DevelopmentChorionic GonadotropinUterusPregnancy Trimester, FirstBlastomeresOocytesPregnancy Trimester, ThirdBirth RatePregnancy, TwinEmbryo Culture TechniquesEndometriumPreimplantation DiagnosisPregnancy Complications, CardiovascularPregnancy TrimestersMenotropinsOvarian Hyperstimulation SyndromeMaternal AgePregnancy Reduction, MultifetalMorulaGestational AgeGene Transfer TechniquesProgesteroneVitrificationPregnancy in DiabeticsPregnancy, High-RiskInsemination, ArtificialPregnancy Trimester, SecondPregnancy MaintenanceFallopian Tube DiseasesEmbryo LossOocyte RetrievalTime FactorsFetal DeathRetrospective StudiesCloning, OrganismPregnancy Complications, NeoplasticPregnancy in AdolescenceSuperovulationFertilizationInfant, NewbornPlacentaPregnancy Complications, InfectiousNuclear Transfer TechniquesTripletsProspective StudiesBuserelinChorionic Gonadotropin, beta Subunit, HumanZona PellucidaPregnancy ProteinsUltrasonographyLuteal PhaseFallopian TubesBirth WeightCulture TechniquesCatheterizationMultiple Birth OffspringEstradiolFertility Agents, FemaleGene Transfer, HorizontalFollicle Stimulating HormoneZygoteSpermatozoaOvaryTwinning, MonozygoticPregnancy, UnplannedFreezingPregnancy, UnwantedGene Expression Regulation, DevelopmentalSurrogate Mothers