CoughInfant, PrematureInfant, NewbornWhooping CoughInfant, Premature, DiseasesInfant CareInfant FoodAntitussive AgentsInfant FormulaInfant BehaviorInfant MortalitySudden Infant DeathInfant, Newborn, DiseasesInfant Nutritional Physiological PhenomenaInfant, Very Low Birth WeightInfant, Low Birth WeightBreast FeedingInfant WelfareInfant, Extremely Low Birth WeightChild DevelopmentMilk, HumanGestational AgePregnancyCapsaicinInfant, Extremely PrematureInfant, Small for Gestational AgeBottle FeedingCitric AcidRespiratory SoundsBirth WeightCodeineIntensive Care Units, NeonatalCryingReflexMothersExpectorantsInfant Nutrition DisordersProspective StudiesRespiratory Distress Syndrome, NewbornBronchopulmonary DysplasiaInfectious Disease Transmission, VerticalRespiratory Tract InfectionsChronic DiseaseBronchitisBordetella pertussisIntensive Care, NeonatalRespiration DisordersAsthmaDevelopmental DisabilitiesApneaRespiratory Tract DiseasesIncubators, InfantAdministration, InhalationInfant EquipmentTime FactorsPertussis VaccineNasal DecongestantsRisk FactorsGastroesophageal RefluxCommon ColdDiarrhea, InfantileRespiratory Function TestsEnterocolitis, NecrotizingMother-Child RelationsBronchial Provocation TestsFollow-Up StudiesMaternal BehaviorSucking BehaviorTerm BirthSputumPregnancy Complications, InfectiousGuaifenesinAge FactorsRetinopathy of PrematurityLarynxCohort StudiesDouble-Blind MethodTreatment OutcomeBronchiolitisRetrospective StudiesNeonatal ScreeningForced Expiratory VolumeGrowth