PregnancyPregnancy ComplicationsPregnancy, High-RiskPregnancy OutcomePrenatal DiagnosisUltrasonography, PrenatalPre-EclampsiaInfant, NewbornPregnancy Complications, CardiovascularPregnancy, AnimalPregnancy, EctopicPregnancy Trimester, FirstHypertension, Pregnancy-InducedPregnancy Complications, HematologicPregnancy Complications, NeoplasticAbortion, SpontaneousFemale Urogenital Diseases and Pregnancy ComplicationsPregnancy Trimester, ThirdPregnancy Trimester, SecondFetal Growth RetardationPlacentaPremature BirthAbruptio PlacentaePregnancy Complications, InfectiousPregnancy, MultiplePregnancy RatePregnancy, TwinGestational AgePregnancy TrimestersUterine ArteryPregnancy TestsPlacenta DiseasesFetal DeathObstetric Labor, PrematurePregnancy ProteinsCivil DisordersEclampsiaPregnancy in DiabeticsPostoperative ComplicationsCongenital AbnormalitiesDiabetes, GestationalTrophoblastsPregnancy, TubalPlacental CirculationCesarean SectionPreconception CareUterusPrenatal CarePregnancy in AdolescenceObstetric Labor ComplicationsBirth WeightStillbirthAbortion, HabitualMaternal AgeParityInfant, Small for Gestational AgeRisk FactorsMaternal-Fetal ExchangePregnancy, UnplannedRetrospective StudiesPregnancy, UnwantedDelivery, ObstetricPlacentationFertilization in VitroAntibodies, AntiphospholipidProspective StudiesPlacental InsufficiencyFetal DevelopmentMultiple Birth OffspringInfant, Low Birth WeightReproductive Techniques, AssistedDeciduaPregnancy, ProlongedMaternal WelfarePregnancy Complications, ParasiticCohort StudiesAntiphospholipid SyndromeFetal Membranes, Premature RuptureAbortion, InducedPregnancy, AbdominalOdds RatioPregnancy MaintenanceEmbryo ImplantationEmbryo TransferLogistic ModelsThrombophiliaTreatment OutcomeRisk AssessmentPrenatal Exposure Delayed EffectsTime FactorsPregnancy Reduction, MultifetalIncidenceInfant, PrematureNorwayHomocysteineCase-Control StudiesIntraoperative ComplicationsProgesteroneInfertility, FemaleQuestionnaires