In the Guttmacher Institute poll of women having abortions in 2008 (see p. 9), about 1 in 5 (20%) claimed to be born-again, evangelical, charistmatic, or fundamentalist.
The report is clear in a footnote, however, that this number shouldn’t be compared to the previous poll result (in 2000) that 13% of women having abortions claimed to be evangelical or born-again, because the question was worded differently on the two polls.
Human Beings Matter More 