PolandPoland SyndromeChild WelfareDisabled ChildrenChild BehaviorChild Health ServicesChild RearingChild, InstitutionalizedChild Behavior DisordersChild PsychologyChild of Impaired ParentsDental Care for ChildrenChild, OrphanedParentsRural PopulationPrevalenceChild Nutrition DisordersChild LanguageChild Nutritional Physiological PhenomenaAge FactorsRisk FactorsUrban PopulationChild MortalityEurope, EasternQuestionnairesInfant, NewbornSocialismCross-Sectional StudiesMothersIncidenceSeasonsParent-Child Relations