1. Unintended Pregnancy in the United States
2. 2.SK Henshaw , 1998 , op. cit. (see reference 1).
3. 3.Ibid.LF Beck , Prevalence of selected maternal behaviors and experiences, Pregnancy Risk Assessment Monitoring System (PRAMS) , 1999 , Morbidity and Mortality Weekly Report, 2002, 51(SS-2):1-27;.