Pregnancy, TwinTwinsPregnancyDiseases in TwinsPregnancy, MultiplePregnancy OutcomeTwins, MonozygoticPregnancy ComplicationsTwins, DizygoticPregnancy, AnimalTwins, ConjoinedPregnancy Trimester, FirstPregnancy, EctopicFetofetal TransfusionGestational AgeFetal DeathPregnancy Trimester, ThirdPregnancy RatePregnancy Trimester, SecondUltrasonography, PrenatalPregnancy in DiabeticsPregnancy Complications, CardiovascularPregnancy TestsPregnancy Reduction, MultifetalChorionPregnancy TrimestersPregnancy Complications, NeoplasticDiabetic RetinopathyInfant, NewbornPregnancy, High-RiskDiabetic NephropathiesEmbryo TransferPregnancy, TubalFertilization in VitroAbortion, SpontaneousTwinning, MonozygoticCesarean SectionPre-EclampsiaPregnancy in AdolescencePregnancy ProteinsObstetric Labor, PrematurePregnancy Complications, InfectiousPlacentaTwin Studies as TopicFetal Growth RetardationMaternal AgePremature BirthBirth WeightTripletsDiabetes Mellitus, ExperimentalPregnancy, UnplannedPrenatal DiagnosisHydatidiform MolePregnancy, UnwantedDelivery, ObstetricReproductive Techniques, AssistedSperm Injections, IntracytoplasmicCongenital AbnormalitiesSingle Umbilical ArteryDiabetic AngiopathiesParityPregnancy Complications, HematologicFetal DiseasesEmbryo ImplantationUterusFetoscopyPregnancy, ProlongedHypertension, Pregnancy-InducedDiabetic FootFetal WeightAmniocentesisFetal DevelopmentCrown-Rump LengthRetrospective StudiesProspective StudiesAbortion, InducedPregnancy, AbdominalRisk FactorsOocyte DonationFetusPerinatal MortalityAmniotic FluidPregnancy Complications, ParasiticLabor, ObstetricNuchal CordChorionic Gonadotropin, beta Subunit, HumanPregnancy, TripletPregnancy MaintenancePolyhydramniosDiabetes Mellitus, Type 1Prenatal CareMaternal Serum Screening TestsInfertility, FemaleUmbilical ArteriesDiabetes Mellitus, Type 2Maternal-Fetal ExchangeReproductive TechniquesInsemination, ArtificialCervix UteriPrenatal Exposure Delayed Effects