Fetal HeartHeart Rate, FetalHeartFetal MonitoringMusclesCardiotocographyHeart RateUltrasonography, PrenatalMuscle ProteinsMuscle, SmoothPregnancyHeart Defects, CongenitalMuscle, SkeletalEchocardiography, Four-DimensionalMuscle Fibers, SkeletalMuscle, Smooth, VascularFetal MovementGestational AgeFetal DiseasesMuscle DevelopmentFetal DistressFetal HypoxiaMuscle ContractionUmbilical ArteriesFetusHeart FailureMuscle FatigueMuscle Fibers, Fast-TwitchMuscle DenervationMyocardiumHeart BlockCanrenoic AcidMuscle Fibers, Slow-TwitchPregnancy Trimester, SecondHeart DiseasesMitochondria, MuscleEchocardiography, Three-DimensionalMyocytes, Smooth MuscleMagnetocardiographyUltrasonography, DopplerHeart TransplantationPregnancy Trimester, ThirdHeart ValvesLabor, ObstetricNeck MusclesOculomotor MusclesPregnancy Trimester, FirstPapillary MusclesMuscle, StriatedMuscle SpindlesMuscle RelaxationRespiratory MusclesCardiac VolumeMuscle WeaknessMuscle CellsTime FactorsAbdominal MusclesBradycardiaQuadriceps MuscleEchocardiographySheepFetal DevelopmentPregnancy OutcomeMasseter MuscleMyocardial ContractionAbortion, ThreatenedFacial MusclesMasticatory MusclesBlood Flow VelocityPrenatal DiagnosisMyocytes, CardiacMaternal-Fetal ExchangeIntercostal MusclesElectromyographyHeart AtriaMuscular AtrophyIsometric ContractionRats, Sprague-DawleyRNA, MessengerApgar ScoreHemodynamicsProspective StudiesSatellite Cells, Skeletal MuscleFetal Growth RetardationEchocardiography, Doppler, ColorRabbitsPectoralis MusclesInfant, NewbornCalciumMuscular DiseasesMyofibrilsPerinatologyCrown-Rump LengthElectronics, MedicalCells, CulturedHeart SeptumPregnancy ComplicationsCardiomegalyElectric StimulationAnalgesia, Obstetrical