Bed RestPregnancyHead-Down TiltPregnancy OutcomeWeightlessness SimulationPregnancy ComplicationsWeightlessness CountermeasuresRestPregnancy, AnimalInfant, PrematurePremature BirthCardiovascular DeconditioningInfant, NewbornPregnancy, EctopicObstetric Labor, PrematureGestational AgeSpace FlightBedsPregnancy Trimester, FirstPregnancy Trimester, ThirdWeightlessnessPregnancy RatePregnancy Complications, CardiovascularPregnancy Trimester, SecondPregnancy, MultiplePregnancy TrimestersPregnancy TestsPregnancy Complications, InfectiousPregnancy in DiabeticsOrthostatic IntoleranceInfant, Premature, DiseasesPregnancy, TubalPregnancy Complications, NeoplasticPregnancy in AdolescencePregnancy, High-RiskLower Body Negative PressureAbortion, SpontaneousFetal Membranes, Premature RuptureInfant, Low Birth WeightPregnancy ProteinsBirth WeightPre-EclampsiaPlacentaPregnancy, UnplannedPregnancy, UnwantedTime FactorsChorioamnionitisFetal DeathPregnancy Complications, HematologicPregnancy, TwinTerm BirthUterine Cervical IncompetenceAmniotic FluidPrenatal CareUltrasonography, PrenatalPregnancy, ProlongedUterusBed OccupancyProspective StudiesInfant, Small for Gestational AgeSupine PositionFetal Growth RetardationParityPlasma VolumeRisk FactorsAbortion, InducedMaternal AgePregnancy Complications, ParasiticExerciseLabor, ObstetricMuscular AtrophyInfant, Extremely PrematureCesarean SectionMuscle, SkeletalEarly AmbulationPregnancy, AbdominalMaternal-Fetal ExchangePrenatal Exposure Delayed EffectsTocolytic AgentsPregnancy MaintenanceFertilization in VitroAbortion, ThreatenedEmbryo TransferHypotension, OrthostaticEmbryo ImplantationTwinsStillbirthFetusDelivery, ObstetricHypertension, Pregnancy-InducedInfant, Very Low Birth WeightCohort StudiesHypovolemiaFetal DevelopmentVascular CapacitancePregnancy Reduction, MultifetalRespiratory Distress Syndrome, NewbornProgesteroneAmino Acids, EssentialDecidua