title: Measurement problems in assessing trends in unwanted fertility.
authors.forename: Sarah R
authors.initials: SR
authors.lastname: Hayford
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Wildsmith
authors.forename: Karen Benjamin
authors.initials: KB
authors.lastname: Guzzo
mesh_terms: D000293:Adolescent; D005260:Female; D005298:Fertility; D006306:Health Surveys; D006801:Humans; D011247:Pregnancy; D011275:Pregnancy, Unwanted