PregnancyPregnancy ComplicationsPregnancy, High-RiskPregnancy OutcomePrenatal DiagnosisUltrasonography, PrenatalPre-EclampsiaInfant, NewbornHypertension, Pregnancy-InducedPregnancy Complications, CardiovascularPregnancy Complications, HematologicFemale Urogenital Diseases and Pregnancy ComplicationsPregnancy Trimester, FirstPregnancy, EctopicAbortion, SpontaneousPregnancy Complications, NeoplasticFetal Growth RetardationAbruptio PlacentaePremature BirthPregnancy, AnimalPlacentaRisk FactorsPregnancy Trimester, SecondUterine ArteryPregnancy Trimester, ThirdCivil DisordersPostoperative ComplicationsPlacenta DiseasesPregnancy Complications, InfectiousEclampsiaPregnancy, TwinObstetric Labor, PrematurePlacental CirculationGestational AgeTrophoblastsDiabetes, GestationalCongenital AbnormalitiesFetal DeathPreconception CarePregnancy, MultipleCesarean SectionObstetric Labor ComplicationsStillbirthPrenatal CareInfant, Small for Gestational AgeUterusBirth WeightAbortion, HabitualPregnancy ProteinsPregnancy RateMaternal AgeRetrospective StudiesParityAntibodies, AntiphospholipidProspective StudiesPlacental InsufficiencyPregnancy TrimestersPlacentationMultiple Birth OffspringPregnancy TestsDelivery, ObstetricCohort StudiesMaternal-Fetal ExchangeRisk AssessmentPregnancy in DiabeticsFetal DevelopmentPregnancy, TubalAntiphospholipid SyndromeOdds RatioMaternal WelfareReproductive Techniques, AssistedCardiovascular DiseasesInfant, Low Birth WeightFetal Membranes, Premature RuptureFertilization in VitroLogistic ModelsPregnancy in AdolescenceDeciduaThrombophiliaTreatment OutcomeHomocysteineUnited StatesIncidenceCase-Control StudiesPregnancy, UnplannedPrevalencePregnancy, UnwantedNorwayIntraoperative ComplicationsQuestionnairesFollow-Up StudiesBiological MarkersTime FactorsPregnancy Complications, ParasiticInfant, PrematureConfidence IntervalsPregnancy, ProlongedAbortion, InducedDiabetes ComplicationsRisk