title: [There are many variations in beginning and duration of the procreative period].
mesh_terms: D000349:Africa; D000367:Age Factors; D000569:Americas; D001208:Asia; D001723:Birth Rate; D017691:Caribbean Region; D002489:Central America; D003267:Contraception; D003625:Data Collection; D003710:Demography; D019049:Developed Countries; D003906:Developing Countries; D005191:Family Characteristics; D005193:Family Planning Services; D005298:Fertility; D007843:Latin America; D008017:Life Expectancy; D008136:Longevity; D008393:Marriage; D008423:Maternal Age; D009026:Mortality; D009656:North America; D010139:Pacific Islands; D010290:Parents; D011153:Population; D011154:Population Characteristics; D011157:Population Dynamics; D012106:Research; D013020:South America
keywords: Africa; Age Factors; Americas; Asia; Caribbean; Central America; Comparative Studies; Contraception; Demographic Factors; Demographic Surveys; Developed Countries; Developing Countries; Family And Household; Family Characteristics; Family Planning; Family Size; Fertility Surveys; Latin America; Length Of Life; Life Expectancy; Marriage; Marriage Age; Marriage Patterns; Maternal Age; Mortality; North America; Nuptiality; Oceania; Parental Age; Population; Population Characteristics; Population Dynamics; Population Statistics; Research Methodology; South America; Studies; Surveys; World Fertility Surveys