The survey on which the study is based was the Guttmacher Institute’s 15th census of all known abortion providers in the United States.
The study, “Abortion Incidence and Services in the United States, 2008,” [http://www.guttmacher.org/pubs/journals/4304111.pdf] has been published online and will appear in the March 2010 issue of Perspectives on Sexual and Reproductive Health.
Some Methods of "Birth Control" are not highly successful at stopping sperm; they are much less successful at stopping bacteria and viruses that cause STDs.
Some methods have even been shown to increase the danger of STD infection.
