Infant MortalitySudden Infant DeathIllegitimacyInfant, NewbornBirth WeightBirth CertificatesDeath CertificatesCause of DeathVital StatisticsNational Center for Health Statistics (U.S.)Maternal AgeInfant, Low Birth WeightFetal DeathWalesInfant CarePrenatal CareBirth OrderCongenital AbnormalitiesUnited StatesEnglandGestational AgeIndians, North AmericanPregnancyMothersAir PollutionAfrican Continental Ancestry GroupInfant, PrematureEuropean Continental Ancestry GroupEducational StatusAir PollutantsSocial ClassRiskRisk FactorsSocioeconomic FactorsOdds Ratio