Premature BirthObstetric Labor, PrematureCerclage, CervicalPregnancyPregnancy OutcomeInfant, PrematureInfant, NewbornGestational AgeChorioamnionitisFetal Membranes, Premature RuptureInfant, Low Birth WeightPregnancy Trimester, SecondDelivery, ObstetricPregnancy ComplicationsCervical RipeningDrug Delivery SystemsPregnancy Trimester, ThirdCervix UteriAmniotic FluidUterine Cervical IncompetenceTocolysisInfant, Small for Gestational AgeInfant, Premature, DiseasesPregnancy Complications, InfectiousUterine MonitoringPregnancy, High-RiskTocolytic AgentsBirth WeightExtraembryonic MembranesVaginosis, BacterialFetal Growth RetardationCesarean SectionRisk FactorsParityStillbirthPregnancy, MultipleCervical Length MeasurementUltrasonography, PrenatalMaternal AgeFetal DeathPregnancy, TwinPre-EclampsiaBetamethasonePlacentaProspective StudiesTerm BirthPerinatal MortalityPlacenta DiseasesInfant MortalityUterine ContractionAbruptio PlacentaeUreaplasma InfectionsGravidityTwinsPrenatal CareCohort StudiesHypertension, Pregnancy-InducedLabor, ObstetricPlacenta PreviaUterine HemorrhageAbortion, SpontaneousVaginaInfant, Very Low Birth WeightPregnancy Trimester, FirstHydroxyprogesteronesPregnancy Complications, CardiovascularRetrospective StudiesAmniocentesisOdds RatioApgar ScoreLogistic ModelsCardiotocographyUterusTripletsAmnionUreaplasma urealyticumPerinatal CareWomen, WorkingFetusFetal Organ MaturityInfant, Extremely PrematureMaternal ExposureBirth CertificatesIntensive Care Units, NeonatalAntitrichomonal AgentsMaternal WelfareCongenital AbnormalitiesLabor, InducedMultiple Birth OffspringObstetric Labor ComplicationsAdministration, IntravaginalPregnancy Complications, ParasiticDrug CarriersAbortion, ThreatenedDenmarkParturitionCase-Control StudiesChorionNorwayRespiratory Distress Syndrome, Newborn