Labor OnsetPregnancy, ProlongedLabor, ObstetricLabor, InducedAtrial Premature ComplexesCervical RipeningCervical Length MeasurementDelivery, ObstetricPregnancyParityCervix UteriLabor PainGestational AgeObstetric Labor, PrematureObstetric Labor ComplicationsTrial of LaborLabor PresentationLabor Stage, ThirdCesarean SectionOxytocicsMyometriumAnalgesia, EpiduralUterine ContractionTerm BirthTocolytic AgentsAmnionParturitionExtraembryonic MembranesFetal MonitoringChorioamnionitisFetal Membranes, Premature RuptureAmniotic FluidPregnancy OutcomeAnesthesia, Obstetrical