Bed RestMothersHead-Down TiltWeightlessness SimulationWeightlessness CountermeasuresRestCardiovascular DeconditioningSpace FlightBedsWeightlessnessOrthostatic IntoleranceLower Body Negative PressurePregnancyMother-Child RelationsBed OccupancyInfant, NewbornSupine PositionMuscular AtrophyExercisePlasma VolumeMuscle, SkeletalEarly AmbulationTime FactorsHypotension, OrthostaticPregnancy-Associated Plasma Protein-AHypovolemiaMiocamycinVascular CapacitanceBreast FeedingPregnancy Trimester, FirstAmino Acids, EssentialBacteriophage muImmobilization